What should the administrator verify to ensure that the conversion is successful?

The administrator at Universal Containers needs to convert a lookup relationship to a master-detail relationship.

What should the administrator verify to ensure that the conversion is successful?
A . The lookup field is required on the child object.
B . No roll-up summaries exist on the lookup object.
C . The owner is the same for all related records
D . The lookup field in all records contains a value.

Answer: D