The correct answer is: a) Chennai and Tuticorin.
Chennai is the capital of Tamil Nadu and the sixth largest city in India. It is a major port city and a major economic and cultural center. Tuticorin is a port city in the Indian state of Tamil Nadu. It is located on the southeastern coast of India, on the Bay of Bengal. It is the second largest port in Tamil Nadu after Chennai.
The other options are incorrect because they are not major ports in Tamil Nadu. Madurai is a city in the Indian state of Tamil Nadu. It is the third largest city in Tamil Nadu after Chennai and Coimbatore. Coimbatore is a city in the Indian state of Tamil Nadu. It is the second largest city in Tamil Nadu after Chennai. Trichy is a city in the Indian state of Tamil Nadu. It is the fourth largest city in Tamil Nadu after Chennai, Coimbatore, and Madurai.