How does an adiabatic process compare to an isentropic process? A. Adiabatic heat transfer is not equal to zero; isentropic heat transfer is zero B. Both heat transfer = 0; isentropic: reversible C. Adiabatic heat transfer = 0; isentropic: heat transfer is not equal to zero D. Both heat transfer is not equal to zero; isentropic: irreversible