Question

What continent includes the coordinates of 90 degrees latitude and 30 degrees longitude?

Answer 1

90 degrees latitude means at the Pole: 90 degrees North latitude would mean the North Pole, and 90 degrees South latitude would mean the South Pole.

North Pole is in an ocean: the arctic ocean. So it must be the South Pole. We don't even need to look for the longitude: it's Antarctica.