Answer:
d. Work is done on the gas
Step-by-step explanation:
We are considering an isobaric compression, which means:
- Isobaric: the pressure of the gas is constant
- Compression: the volume of the gas is decreasing
For an isobaric compression, the volume done BY the gas is

where
p is the gas pressure
is the final volume of the gas
is the initial volume of the gas
If the sign of W is positive, it means that the gas is doing work on the surrounding; if the sign of W is negative, it means that the surrounding is doing worn ON the gas.
In this case, since it is a compression, we have that the final volume is smaller than the initial volume:

Therefore, the sign of W is negative, and therefore work is done ON the gas by the surroundings.