A Fixed Amount of an Ideal Monatomic Gas Is Maintained

Multiple Choice

A fixed amount of an ideal monatomic gas is maintained at constant volume as it is cooled by 50 K. This feat is accomplished by removing 400 J of energy from the gas. How much work is done by
The gas during this process?

A) 400 J
B) 200 J
C) -400 J
D) -200 J
E) 0 J