While drilling loaded as shown in Sample Load Form Number 4 (Drilling), the DEEP DRILLER suffers a sudden unexpected starboard and aft inclination. The wind and waves are light. What might have caused the inclination?

Correct Answer: Option C — The drilling crew has dumped the mud.

Dumping drilling mud rapidly alters the vessel's vertical and transverse center of gravity, causing an immediate change in draft and stability. Unlike slow internal leaks, discharging heavy mud generates a sudden, noticeable shift in trim and list.