How should this be accomplished?

An app builder is creating a custom object called Testimonial__c and wants toconnect Testimonial__c records with both the submitter’s Contact record and Account record. If the Account is deleted, the Testimonial__c should also be deleted. If the Contact is deleted, but the Account remains, the Testimonial__c should remain.

How should this be accomplished?
A . Make both the Contact and Account fields required on the Testimonial__c object and create lookup relationships from Testimonial__c to Contact and to Account.
B. Create a master-detail relationship from Testimonial__c to Accountand a lookup relationship from Testimonial__c to Contact.
C. Make Testimonial__c a junction object between Account and Contact using master-detail relationships.
D. Create a lookup relationship from Testimonial__c to Account and a master-detail relationship from Testimonial__c to Contact.

Answer: B