This is a isoentropic process or you can say adibatic process also(dS=0 means dQ=0).. check all the options by putting them in equation of adibatic process, u will get ur ans...
Entropy of the gas remains unchanged (it is sometimes written as isentropic process) which clearly means dS =0, which means dQ =0 (as dQ = T*dS). Hence isentropic process is adiabe...
Option B is currect.As dS=0 thus the process here is adiabatic. dQ=TdS .so using pv^ (gamma) = const , gives the solution .I have checked all the solution ,thinking it as a MSQ, fe...