Which syntax turns an existing constraint on?

Q. Which syntax turns an existing constraint on?

A. ALTER TABLE table_name ENABLE constrain_name

B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constrain_name

C. ALTER TABLE table_name ENABLE CONSTRAINT constraint_name

D. ALTER TABLE table_name STATUS ENABLE CONSTRAINT constraint_name

E. ALTER TABLE table_name TURN ON CONSTRAINT costrant_name

F. ALTER TABLE table_name TURN ON CONSTRAINT constraint_name

Answer: C