INLAND ONLY What do the lights shown in illustration D075RR below represent?

Correct Answer: Option B — vessel pushing ahead

33 CFR 83.24(d) (Rule 24) specifies that a power-driven vessel pushing ahead or towing alongside must exhibit sidelights and a sternlight. When pushing ahead, the vessel must also show two masthead lights in a vertical line, identifying the composite unit as a single power-driven vessel.