Dear Sanika ,

Whenever heat is applied to a closed system , there is a change in volume .

so PV = nRT at the initial phase will be the same for PV = nRT after heating it

let us take initial as P1V1 and final as P2V2

work done during an expansion is -PΔV ,

since P is also changing the above formula cannot be used and V changes , V increases when heated (because the piston moves up when it is heated)

so the final answer is (D) THE PRESSURE OF THE GAS WILL INCREASE THROUGHOUT THE PROCESS.

we cannot say that a gas is monoatomic or diatomic from the given information , so they have to be ignored .