If your passenger vessel has been issued a stability letter, it must be __________.

Correct Answer: Option D — posted in the pilothouse

46 CFR 170.110 mandates that a stability letter issued to a vessel must be posted in the pilothouse. This ensures the Master has immediate, unobstructed access to critical stability data, including limitations on loading, ballasting, and operating conditions, which are essential for maintaining the vessel's safe operation and seaworthiness.