Which Apex method must be used to make sure only allowed fields are shown to the users?

Universal Containers (UC) uses a custom Visualforce page to display shipment tracking information (custom object, private OWD) to field manager and agents. The IT team wants to make sure that users have access to only the information that is allowed.

Which Apex method must be used to make sure only allowed fields are shown to the users?
A . isReadable()
B. isShowable()
C. isAccessible()
D. isViewable()

Answer: C