Which of the following is geographically closest to Great Nicobar?

The correct option is Sumatra.

Step-by-Step Explanation:

1. Geographical Location of Great Nicobar:
Great Nicobar is the southernmost island of the Andaman and Nicobar Islands territory of India. Its southernmost tip, known as Indira Point, is situated at approximately 6° 45′ N latitude.

2. Proximity to Sumatra:
The northern tip of the Indonesian island of Sumatra (specifically Aceh province) is located just south of Great Nicobar, across the Great Channel (also known as the Six Degree Channel). The distance between Indira Point and the northern tip of Sumatra is only around 150 km to 200 km (approx. 90-100 nautical miles).

3. Comparison with Other Options:
- Sumatra (Indonesia): ~150 km to 200 km from Great Nicobar.
- Sri Lanka: ~1,400 km to the west.
- Java (Indonesia): ~2,000 km to the southeast.
- Borneo: ~2,200 km to the east/southeast.

Therefore, Sumatra is geographically the closest island to Great Nicobar among all the choices provided.