A) Process-I is not isochoric, V is decreasing . B)Process-II is isothermal expansion ΔU=0,W>0ΔQ>0 C)Process-IV is isothermal compression ,ΔU=0,W<0ΔQ<0 D) Process-I and III are NOT isobaric because in isobaric process T∝V hence isobaric T-V graph will be linear.