BOTH INTERNATIONAL & INLAND Which statement is TRUE concerning fog signals?

Correct Answer: Option C — A vessel aground may sound a whistle signal.

Rule 35(g) explicitly permits a vessel aground to sound an optional whistle signal (one short, one prolonged, one short) in addition to the mandatory bell and gong signals. This provides an extra layer of safety by helping approaching vessels identify the stationary, grounded vessel's position in low visibility.