I would make a Canvas as a child of the gameobject with the rigidbody2d/collider2d components, then put the button on that canvas, and then in your code above, keep a reference to the canvas and the button that lives there.

Then, you can use GraphicRaycaster.Raycast. Modified version of the source code in the Unity Docs:

// Attach this script to your Canvas GameObject.
// Also attach a GraphicsRaycaster component to your canvas by clicking the 
//     Add Component button in the Inspector window.
// Also make sure you have an EventSystem in your scene

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections.Generic;

public class RaycasterTester : MonoBehaviour
{
    GraphicRaycaster m_Raycaster;

    void Start()
    {
        //Fetch the Raycaster from the GameObject (the Canvas)
        m_Raycaster = GetComponent<GraphicRaycaster>();      
    }

    public bool TestTouch(Touch touch, GameObject target)
    {
        //Set up the new Pointer Event
        PointerEventData pointerEventData = new PointerEventData(EventSystem.current);
        //Set the Pointer Event Position to that of the touch position
        pointerEventData.position = touch.position;

        //Create a list of Raycast Results
        List<RaycastResult> results = new List<RaycastResult>();

        //Raycast using the Graphics Raycaster and touch position
        m_Raycaster.Raycast(pointerEventData, results);

        foreach (RaycastResult result in results)
        {
            if (result.gameObject == target) return true;
        }

        return false;
    }
}

So basically the hierarchy looks something like this at runtime:

Flipper object [ Rigidbody2D, Collider2D, questionScript (references RaycasterTester and Button) ]
L Canvas object [ Canvas (world space), GraphicRaycaster, RaycasterTester ]
  L Button object [ Button, Image, hitButtonScript (?) ]

(somewhere in scene) [ EventSystem ]

Then, in the Question Script, get a reference to the instance of the above script then call the TestTouch method:

foreach (Touch touch in Input.touches)
{
    if (touch.phase == TouchPhase.Stationary 
            && raycasterTester.TestTouch(touch, hitButton.gameObject))
    {
        GetComponent<Rigidbody2D>().MoveRotation(80);
          
        // break to avoid being turned by multiple touches?
        // break;
    }
} 

By the way, if the question code is happening in Update, it might be best to call GetComponent<Rigidbody2D> in Start (or, if the Rigidbody2D is ever removed and/or replaced, at those times as well) and cache the results, since it can be an expensive operation.

Actually better than checking this manually would indeed be a UI.Button + additionally implementing a custom extension using the IPointerDownHandler and IPointerUpHandler etc interfaces (note: the linked API is 2018, but this applies to 2020 as well, they just moved the API to a package and there it is not so well explained) like

public class HoldButton : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerEnterHandler, IPointerExitHandler
{
    // Called once when the button goes down (comparable to GetKeyDown)
    public UnityEvent OnButtonDown;
    // Called every frame while the button is pressed (comparable to GetKey)
    public UnityEvent WhilePressed;
    // Called once when the button goes up (comparable to GetKeyUp)
    public UnityEvent OnButtonUp;

    // Called if you hover with the mouse or drag an existing touch into the button
    public void OnPointerEnter(PointerEventData pointerEventData)
    {
        // Not sure if needed for OnPointerExit to work, doing nothing else
    }

    // Called when mouse or touch leaves the button
    public void OnPointerExit(PointerEventData pointerEventData)
    {
        OnButtonUp.Invoke();
        StopAllCoroutines();
    }

    // Called if you press the mouse or begin a touch over this button
    public void OnPointerDown(PointerEventData pointerEventData)
    {
        OnButtonDown.Invoke();
        StartCoroutine (WhilePressedRoutine());
    }

    // Called if you release mouse or touch over this button
    public void OnPointerUp(PointerEventData pointerEventData)
    {
        OnButtonUp.Invoke();
        StopAllCoroutines();
    }

    private IEnumerator WhilePressedRoutine()
    {
        while(true)
        {
            WhilePressed.Invoke();
            yield return null;
        }
    }
}

In these UnityEvents you can reference your handler methods just like in the UI.Button.onClick via the Inspector or on runtime via script.

So you can either attach this on a UI element (like a Button) and let the EventSystem of the scene call the pointer handlers.

Or you can even attach this to normal 3D objects! In such case this requires additionally

• A collider on your 3D object
• A PhysicsRaycaster component on your Camera

Or for a 2D object accordingly

• A Collider2D on your object
• A Physics2DRaycaster on your Camera

These interfaces work for both, mouse and touch input (except for the pointer enter probably because a touch can't just hover - at least not on all phones ;) )