The correct answer is B) must be lighted at all times. According to the Navigation Rules, both International and Inland, any barge being towed or pushed at night must be lighted at all times, regardless of its position relative to the towing vessel or whether it is manned. The rules require barges to display the appropriate lights to make them visible to other vessels and prevent collisions. Options A, C, and D are incorrect because they do not fully comply with the lighting requirements for barges being towed at night.