What is the optimum sharing technique that can achieve the requirements?

Universal Containers (UC) delivers training and courses to students and companies. UC is implementing a Salesforce Customer Community for its students granting them a Customer Community license. As part of the community requirements, UC asked to give students access to cases that are related to their account in the UC community.

What is the optimum sharing technique that can achieve the requirements?
A . Create a sharing rule to share cases with the students.
B. Create a share group to share cases with the students.
C. Create a sharing set to share cases with the students.
D. Use Apex sharing to share cases with the students.

Answer: C