A

Step 1: Start from the given equation of state for the process:
\[ p = p_0 \left( \frac{V_0}{V} \right)^{\gamma} \]\
where \( p_0 \) and \( V_0 \) are constants, and \( \gamma \) is the heat capacity ratio (Cp/Cv) for the ideal gas.

Step 2: Substitute \( V = V_0 \) into the equation:
\[ p = p_0 \left( \frac{V_0}{V_0} \right)^{\gamma} = p_0 \]\
So, at \( V = V_0 \), the pressure is equal to \( p_0 \).

Step 3: Use the ideal gas law to find the temperature. The ideal gas law is given by:
\[ PV = nRT \]
Since 1 mole of gas is used, \( n = 1 \):
\[ p_0 V_0 = RT \]\
So, we can solve for temperature \( T \):
\[ T = \frac{p_0 V_0}{R} \]

Step 4: The final expression for the temperature of the gas when \( V = V_0 \) is:
\[ T = \frac{p_0 V_0}{R} \]