Which of these is a benefit of fish farming?
A. It poses a risk of disease for wild stocks.
B. It depletes fish populations.
C. It eases the demand on commercial fisheries.
D. It pollutes natural bodies of water.
It's pretty simple really, just find the Benefit. Pollution is definitely a harmful effect, disease is also not a benefit, and depletion of fish population is bad, so easing demand on commercial fisheries is the answer