For the Reaction, 2 Cr²⁺(aq)+ Cl₂(g) 2 Cr³⁺(aq)+ 2 $\rarr$

For the reaction, 2 Cr²⁺(aq) + Cl₂(g) 2 Cr³⁺(aq) + 2 Cl^-(aq) , the value of E°_cell is1.78 V. What is the value of E°_cell for the following reaction?
Cr³⁺(aq) + Cl^-(aq) $\rarr$ Cr²⁺(aq) + ½ Cl₂(g)

A) -1.78 V
B) +0.89 V
C) +1.78 V
D) -0.89 V
E) -3.56 V