At which of the following places in India did the Portuguese build their first fortress ?

Anjidiv
Cannanore
Cochin
Goa

The correct answer is (d), Goa.

The Portuguese built their first fortress in India at Goa in 1510. The fortress was built on the site of an old Hindu temple, and it was named Fort Aguada. The fortress was built to protect Portuguese interests in India, and it was also used as a base for Portuguese trade and exploration.

Anjidiv is a small island off the coast of Goa. The Portuguese built a fort on the island in 1505, but it was abandoned in 1510.

Cannore is a city on the Malabar Coast of India. The Portuguese built a fort at Cannanore in 1505, but it was captured by the Dutch in 1663.

Cochin is a city on the Malabar Coast of India. The Portuguese built a fort at Cochin in 1503, and it remained under Portuguese control until 1663.