In an isothermal expansion,the increase in volume with a decrease in pressure of a gas is greater than in an adiabatic expansion,because .............

• A
  The internal energy of the system does not change in isothermal and adiabatic expansion.
• B
  The temperature remains constant in isothermal expansion,whereas the temperature decreases in adiabatic expansion.
• C
  In isothermal expansion $q = w$,whereas in adiabatic expansion $\Delta U = w$.
• D
  Work is done by the system in an isothermal process,whereas work is done on the system in an adiabatic process.