The number of incorrect statements from the following is ___________.

A. The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.

B. $\mathrm{E_{cell}^{\circ}}$ cell is dependent on the pressure.

C. $\frac{d E^{\theta} \text { cell }}{\mathrm{dT}}=\frac{\Delta_{\mathrm{r}} \mathrm{S}^{\theta}}{\mathrm{nF}}$

D. A cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.