The Oxidation Numbers of P, S, and Cl in H₂PO₂^-

Multiple Choice

The oxidation numbers of P, S, and Cl in H₂PO₂^-, H₂S, and KClO₄ are, respectively

A) -1, -1, +3.
B) +1, -2, +7.
C) +1, +2, +7.
D) -1, -2, +7.
E) -1, -2, +3.