Step 1: Concept Use the Ideal Gas Equation in the form: $\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}$.
Step 2: Meaning $P_2 = 2P_1$ and $T_2 = T_1/2$. We need to find $V_2$.
Step 3: Analysis $V_2 = V_1 (\frac{P_1}{P_2}) (\frac{T_2}{T_1}) = V_1 (\frac{P_1}{2P_1}) (\frac{T_1/2}{T_1}) = V_1 (\frac{1}{2}) (\frac{1}{2})$.
Step 4: Conclusion $V_2 = V_1/4$. The volume becomes one-fourth.
Final Answer: (A)