A gas inside a cylinder is given thermal energy $q$. As the gas expands at constant pressure $p$ from volume $V_0$ to volume $V_F$, it does useful work, as shown. Which expression gives the efficiency of this process?
- A$\frac{p V_0}{q}$
- B$\frac{V_F}{V_0 q}$
- C$\frac{p (V_F - V_0)}{q}$
- D$\frac{V_F - V_0}{V_0 q}$