If a Reducing Agent M Reacts with an Oxidizing Agent

If a reducing agent M reacts with an oxidizing agent Q²⁺ to give M²⁺ and Q, and the equilibrium constant for the reaction is 1.0, then what is the E° value for the oxidation-reduction reaction at 25°C?

A) 0.030 V
B) 1.0 V
C) 0.0 V
D) 0.41 V
E) -1.0 V