How should a Salesforce Admin meet these requirements?

Universal Containers needs to build a partner community that supports multiple business units by providing the following abilities:

• Each business unit can only collaborate with its partner network.

• Partners only see Knowledge articles and content specific to their business unit.

• Some business units allow partners to raise support cases.

• Some partners work with multiple business units.

How should a Salesforce Admin meet these requirements?
A . Build a Community for each business unit and assign partners to the relevant Communities
B . Build one Community and allow the partner profiles to be assigned based on the business unit
C . Build one Community and segment partner visibility by turning off Community User Visibility
D . Build a Community for each business unit and allow partners to have separate login credentials