B,C pretty sure

B C
https://developer.salesforce.com/docs/atlas.en-us.240.0.pages.meta/pages/pages_controller_methods.htm
Getter methods
Pass Data from apex Controller to the Visulaforce page
Setter methods
Pass Data from a Visulaforce page to its Apex Controller
Visualforce doesn’t define the order in which getter methods are called, or how many times they might be called in the course of processing a request.
Visualforce doesn’t define the order in which setter methods are called, or how many times they might be called in the course of processing a request.

I would say B and C

I think option A is wrong it should be
A corresponding Setter method is required for each Getter method.