Repair of structures on a MODU in the vicinity of liquid mud handling areas presents what possible hazard?

Correct Answer: Option C — Flammable gasses may be present.

Liquid mud systems often contain entrained gases from the wellbore, including methane and hydrogen sulfide. Repair work involving hot work or structural modification in these areas poses a severe risk of igniting flammable gases, necessitating rigorous gas testing and the issuance of hot work permits before any repairs commence.