As shown in Fig. below, an ideal gas is confined to a cylinder by a piston. The piston is pushed down slowly so that the gas temperature remains at $$27^\circ C$$. During the compression, 900 J of work is done on the gas. Find the entropy change of the gas.

A

3 J/K

B

-3 J/K

C

-6 J/K

D

6 J/K