Which task can be performed by using a single Data Mani…

Which task can be performed by using a single Data Manipulation Language (DML) statement?

A.
adding a column constraint when inserting a row into a table

B.
adding a column with a default value when inserting a row into a table

C.
removing all data only from one single column on which a unique constraint is defined

D.
removing all data only from one single column on which a primary key constraint is defined