Two cylinders A and B fitted with piston contain equal amount of an ideal diatomic gas at temperature T K. The piston of cylinder A is free to move while that of cylinder B is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise of temperature of the gas in A is \(\mathrm{dT}_{\mathrm{A}}\), then the rise in temperature of the gas in B is \(\left(\gamma=\frac{\mathrm{C}_{\mathrm{p}}}{\mathrm{C}_{\mathrm{v}}}\right)\)

1. A \(\frac{\mathrm{dT}_{\mathrm{A}}}{2}\)
2. B \(\frac{\mathrm{dT}_{\mathrm{A}}}{\gamma}\)
3. C \(\gamma \mathrm{dT}_{\mathrm{A}}\)
4. D \(2 \mathrm{dT}_{\mathrm{A}}\)