What is the longitude of the geographical position of a body whose Greenwich hour angle is 210°30'?

Correct Answer: Option D — 149°30'E

Geographical longitude corresponds directly to Greenwich Hour Angle. When GHA is greater than 180 degrees, the west longitude is found by subtracting GHA from 360 degrees. Conversely, convert western GHA equivalents or calculate eastern longitude by 360° minus GHA, yielding 149°30'E.