A high concentration of hydrogen sulfide gas is most likely to be found in which of the locations listed?

Correct Answer: Option B — Sewage compartment bilges where leaked sewage has accumulated.

Hydrogen sulfide is a byproduct of the anaerobic decomposition of organic matter. Sewage compartments are prime environments for this process, especially where stagnant sewage has accumulated. The resulting H2S gas is extremely toxic and poses a severe respiratory hazard to personnel entering these confined, poorly ventilated spaces.