My page has a dynamically changed pulldown value.

For example:

If radioButtonA = 1, then 
   pulldownB selection = a, b, c
If radioButtonA = 2, then
   pulldownB selection = d, e, f

When I set the radioButtonA to 2, and go to other page. And use back button on that condition, radioButtonA will remains 2 but pulldownB selection will revert to a, b, c.

I know that this is due to how chrome cache its form inputs. What I dont understand is how did it works? (where does it being stored, how long does it preserved etc)

I have tried googling this problem but havent found any official documents for this. Really appreciate if someone can explains or guides me to the correct resources.