In which two ways should the data extension and import be configured?

A marketer is updating a data extension by manually importing a file. The marketer wants to ensure only new records are added to the data extension during the Import process.

In which two ways should the data extension and import be configured? Choose 2 answers
A . Select the update type "Overwrite"
B. Ensure the data extension has a Primary Key
C. Select the update type "Add and Update"
D. Select the update type "Add Only"

Answer: C,D