Which of the following is/are correct filing method(s) for controlled substances?

I. One file for CII, second file for III, IV and V and a third file for non-controlled substances.

II. One file for CII and a second file for III, IV, V and non-controlled substances.

III. One file for controlled and a second file for non-controlled substances.

a. I only
b. I and II only
c. II and III only
d. All