Calculate E° for an Electrochemical Cell Based on the Following ${E}_{\text {red }}^{o}$

Calculate E° for an electrochemical cell based on the following overall reaction: 2H⁺(aq) + Cd(s) ? H₂(g) + Cd²⁺(aq)
If ${E}_{\text {red }}^{o}$ (H⁺) = 0.000 V and ${E}_{\text {red }}^{o}$ (Cd²⁺) = ?0.402 V.

A) ?0.402 V
B) ?0.201 V
C) 0.000 V
D) +0.201 V
E) +0.402 V