If $C_{p}$ and $C_{v}$ are molar specific heats of an ideal gas at constant pressure and volume respectively and $\gamma$ is $C_{p} / C_{v}$,then $C_{p} =$ (where $R$ is the universal gas constant).

• A
  $\frac{\gamma R}{\gamma-1}$
• B
  $\gamma R$
• C
  $\frac{1+\gamma}{1-\gamma}$
• D
  $\frac{R}{\gamma-1}$