The expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for

A. Reversible isothermal volume change

B. Heating of a substance

C. Cooling of a substance

D. Simultaneous heating and expansion of an ideal gas

Please do not use chat terms. Example: avoid using "grt" instead of "great".