A Unit Mass of an Ideal Gas at Temperature T $\Delta$

A unit mass of an ideal gas at temperature T undergoes a reversible isothermal process from volume V₁ to volume V₂ while loosing heat to the surroundings at temperature T in the amount of q. If the gas constant of the gas is R, the entropy change of the gas $\Delta$ s during this process is

A) $\Delta$ s =R ln(V₂/V₁) -q/T
B) $\Delta$ s = R ln(V₂/V₁)
C) $\Delta$ s =R ln(V₁/V₂)
D) $\Delta$ s =R ln(V₁/V₂) -q/T
E) $\Delta$ s= 0