Capt. Neal® wrote:
Rule 30
a) A vessel at anchor shall exhibit where it can best be seen:
1.. in the fore part, an all-round white light or one ball;
2.. at or near the stern and at a lower level than the light
prescribed in subparagraph (i), an all-round white light.
Special anchorage means nothing unless the vessel is less than 20 meters.

The question says a barge greater than fifty meters . . .

The correct answer is two anchor lights as per above.

I hope this helps.

CN

As stated, question 26 was debatable. If you go by the older rules, and
Bart's test was using that, then he was correct, only one light required
as written for the test.
I'm still checking that one as I think you may be right (ROFL), but
since it's become obvious your rules are out of date, I'm giving you a
"wrong" based on what you know.

otn