One mole of an ideal monoatomic gas, contained in a cylinder fitted with movable piston, is originally at $$P_1$$, $$V_1$$ and $$T_1 = 27^\circ\text{C}$$. The gas is slowly heated. Initially $$8.31\,\text{watt-hour}$$ of energy is added to it and at the same time it is allowed to expand at constant pressure to a new state $$P_1$$, $$V_2$$ and $$T_2$$. The correct option is

A

Value of $$T_2$$ is $$1740^\circ\text{C}$$

B

Work done by the gas is $$2160R\,\text{joule}$$

C

Internal energy of the gas increases by $$1440R\,\text{joule}$$

D

$$\frac{V_2}{V_1} = 5.8$$