What does a full purge import do?

What does a full purge import do?
A . Deletes all records for an employee or object from the system based on the import file.
B . Deletes all records for an employee or object from the system, regardless of the import file.
C . Overwrites all records for an employee or object from the system based on the import file.
D . Overwrites all records for an employee or object from the system, regardless of the import file.

Answer: D