【单选题】View the Exhibit and examine the structure of the EMP table. You executed the following command to add a primary key to the EMP table: ALTER TABLE emp ADD CONSTRAINT emp_id_pk PRIMARY KEY (emp_id...
A.
The PRIMARY KEY is created along with a new index.
B.
The PRIMARY KEY is created and it would use an existing unique index.
C.
The PRIMARY KEY would be created in a disabled state because it is using an existing index.
D.
The statement produces an error because the USING clause is permitted only in the CREATE TABLE command.