What lights would be visible from ahead of a 40-meter tug pushing two barges ahead?

A tug pushing two barges ahead is required to exhibit specific lights to ensure safe navigation and visibility. In this scenario, the correct answer indicates that the tug would display sidelights and two masthead lights.

The sidelights, which are green on the starboard side and red on the port side, are essential for indicating the vessel's orientation and direction to other boats approaching from ahead. The two masthead lights serve to signal the presence of the tugboat and its tow; the tug typically displays two masthead lights if it is pushing a tow that exceeds a certain length, thereby increasing its visibility and aiding in identification.

This setup of lights allows other vessels---especially those approaching from ahead---to accurately perceive the size and direction of the tug and the barges it is pushing, ensuring safe navigation in proximity to the towed vessels. By displaying both the sidelights and two masthead lights, the tug communicates not just its position but also its operational status effectively, distinguishing itself from other types of vessels that may only display a single set of lights.