Explanation:

• Chagos Archipelago consists of 58 islands and is located approximately 500 km south of the Maldives in the Indian Ocean.

• The French were the first to colonize Mauritius along with the Chagos Islands in 1715.

• In the late 18th century, the French brought in slave labor from Africa and India to work in newly established coconut plantations.

• However, the UK took control of the region in 1814 after the fall of France’s Napoleon Bonaparte.

• In 1965, the UK constituted the British Indian Ocean Territory (BIOT), of which the Chagos Islands were a central part.

Hence option 4th is correct.