For\[Ag\to A{{g}^{+}}+{{e}^{-}},\] \[E{}^\circ =-0.798V\] \[{{V}^{2+}}+V{{O}^{2+}}+2{{H}^{+}}\to 2{{V}^{3+}}+{{H}_{2}}O,\] \[E\text{ }\!\!{}^\circ\!\!\text{ }=-0.614\text{ }V\] \[{{V}^{3+}}+A{{g}^{+}}+{{H}_{2}}O\to V{{O}^{2+}}+2{{H}^{+}}+Ag,\] \[E{}^\circ =-\,0.438\text{ }V\] Then \[E{}^\circ \]for the reaction \[{{V}^{3+}}+{{e}^{-}}\to {{V}^{2+}}\] is

• A. + 0.255V
• B. \[-\,0.255\,V\]
• C. \[-\,0.254\,V\]
• D. \[-\,1.055\,V\]