Which two islands 2.5 miles apart have a 20-hour time difference?

Maui, United States and Honshu, Japan
Upolu, Samoa and Tokelau, New Zealand
Big Diomede, Russia and Little Diomede, U.S.
Grand Terre, New Caledonia and Moorea, Tahit

The Answer: The correct answer is Big Diomede, Russia and Little Diomede, U.S.