ColRegs Rule 24 states:
A power-driven vessel when towing shall exhibit:
(i) instead of the light prescribed in Rule 23(a)(i) or (a)(ii), two masthead lights in a vertical line. When the length of the tow, measuring from the stern of the towing vessel to the after end of the tow exceeds 200 meters, three such lights in a vertical line
Therefore, the answer should be "A vessel whose tow exceeds 200 meters astern"
But you say the answer is "A vessel not under command, at anchor" which should be 2 all around red lights.
A power-driven vessel when towing shall exhibit:
(i) instead of the light prescribed in Rule 23(a)(i) or (a)(ii), two masthead lights in a vertical line. When the length of the tow, measuring from the stern of the towing vessel to the after end of the tow exceeds 200 meters, three such lights in a vertical line
Therefore, the answer should be "A vessel whose tow exceeds 200 meters astern"
But you say the answer is "A vessel not under command, at anchor" which should be 2 all around red lights.