Your longitude is 124°E, and your local mean time is 0520 on the 5th of the month. The mean time and date at Greenwich is __________.

Correct Answer: Option B — 2104 on the 4th

Converting Local Mean Time to Greenwich Mean Time (UT) at 124° East longitude requires subtracting 8 hours and 16 minutes (at 4 minutes per degree). Subtracting this time interval from 0520 on the 5th crosses midnight, resulting in 2104 on the 4th.