BOTH INTERNATIONAL & INLAND A vessel being towed, if manned, shall sound which fog signal?

Correct Answer: Option B — One prolonged and three short blasts

Rule 35(e) mandates that a vessel being towed, or if more than one vessel is towed, the last vessel of the tow, if manned, shall sound one prolonged blast followed by three short blasts at intervals of not more than two minutes, immediately after the signal of the towing vessel.