Two Unequal,antiparallel Forces

Multiple Choice

Two unequal,antiparallel forces

A) can be replaced by a single force.
B) can be replaced by a couple whose torque equals the torque about the center of mass of the original forces.
C) can be replaced by equal,parallel forces.
D) can be replaced by a single force plus a couple whose torque equals the torque about the center of mass of the original forces.
E) can be replaced by none of these.