Which statement accomplishes this task?

You need to modify the STUDENTS table to add a primary key on the STUDENT_ID
column. The table is currently empty. Which statement accomplishes this task?

A.
ALTER TABLE students ADD PRIMARY KEY student_id;

B.
ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);

C.
ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;

D.
ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);

E.
ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY
(student_id);