The correct answer is Option (3) - Chittagong
Faridpur: It's a city located on the banks of the Padma River, but not a major seaport.
Rajshahi: It's a major city in northwestern Bangladesh and not on the coast, eliminating it as a seaport.
Chittagong: This is the correct answer. Chittagong is the main seaport of Bangladesh, located on the southeastern coast and handling a significant portion of the country's international trade.
Dhaka: While Dhaka is the capital of Bangladesh, it's an inland city on the Buriganga River and not a seaport. | 
