How can an App Builder enable different users to see different fields, based on the case type?

At Universal Containers, multiple departments utilize the Case object for different purposes. Some users submit cases for IT and HR requests. Other users provide customer support with case records .

How can an App Builder enable different users to see different fields, based on the case type?
A . Create different case record types for IT, HR and Customer Support. Assign different page layouts to each record type by profile.
B . Create different case field sets for IT, HR and Customer Support. Assign different field sets by profile.
C . Create different case record types for IT, HR and Customer Support. Assign different page layouts to each record type by role.
D . Create different case field sets for IT, HR and Customer Support. Assign different field sets by role.

Answer: A