The Andaman group of islands and the Nicobar group of islands are separated by latitude. Latitude is an imaginary line that runs horizontally around the Earth and is used to measure distance north or south of the Equator.

Option 1: 8° N latitude. This option is incorrect because it is too far north to separate the Andaman and Nicobar islands.

Option 2: 10° N latitude. This option is the correct answer because it is the latitude that separates the Andaman group of islands and the Nicobar group of islands.

Option 3: 12° N latitude. This option is incorrect because it is too far north to separate the Andaman and Nicobar islands.

Option 4: 13° N latitude. This option is incorrect because it is too far north to separate the Andaman and Nicobar islands.

In conclusion, option 2 (10° N latitude) is the correct answer as it is the latitude that separates the Andaman group of islands and the Nicobar group of islands.