Final answer:
In a master-detail relationship, when a parent record is deleted, all its associated child records are also deleted to maintain referential integrity and prevent orphan records.
Step-by-step explanation:
In a master-detail relationship, when the parent record is deleted, all associated child records are also deleted. This is because in a master-detail relationship, the existence of child records is strictly dependent on the presence of the parent record. Therefore, the correct answer to the question is 2) Child records are deleted. It's important to note that this type of relationship is specifically designed to maintain referential integrity so that no orphan records exist in the system upon the deletion of the master (or parent) record.