The question asks for the city that hosted the multilateral naval exercise MILAN in 2020. MILAN is a well-known naval exercise that is hosted by the Indian Navy.

Let`s dissect each option to determine which one is correct:

Option 1: Port Blair. Port Blair is the capital city of the Andaman and Nicobar Islands in India. While it is a strategic location for naval activities, there is no evidence to suggest that it hosted the MILAN exercise in 2020.

Option 2: Kochi. Kochi, also known as Cochin, is a major port city in the Indian state of Kerala. It is home to the Southern Naval Command of the Indian Navy. It has previously hosted the MILAN exercise in the past. However, there is no confirmation that it hosted the exercise in 2020.

Option 3: Vishakapatnam. Vishakapatnam, also known as Vizag, is a coastal city in the Indian state of Andhra Pradesh. It is home to the Eastern Naval Command of the Indian Navy. It has previously hosted the MILAN exercise and there is evidence to suggest that it hosted the exercise in 2020. Therefore, option 3 is the most likely correct answer.

Option 4