Question 853 Rules of the Road

The correct answer is C) not under command. According to the International and Inland Navigation Rules, a vessel displaying two all-round red lights in a vertical line is indicating that it is "not under command." This means the vessel is unable to maneuver as required by the rules and is therefore unable to keep out of the way of other vessels. The other answer choices are incorrect because they do not match the specific lighting configuration described in the question. Vessels at anchor, pushing a barge, or being towed would display different light signals to indicate their status and navigation.