What must the system administrator check in order for the change to be implemented successfully?

A system administrator wants to change the field type from a lookup field to a master-detail field.

What must the system administrator check in order for the change to be implemented successfully?
A . Make sure that the lookup field has a related record
B . Make sure the lookup value is required
C . Make sure that all lookup fields on the record are filled up
D . Option4

Answer: C