Which is the correct statement
A. For an isothermal change PV= constant
B. In an isothermal process the change in internal energy must be equal to the work done
C. For an adiabatic change `(P_(2))/(P_(1))=((V_(2))/(V_(1)))^(lambda)` where `lambda` is the ratio of specific heats
D. In an adiabatic process work done must be equal to the heat entering the system
