Correct Option: A

A natural harbor is a landform where a part of a body of water is protected and deep enough to furnish anchorage. Many such harbors are rias. Bombay port and Kandla port have natural harbours. Kochi also has a natural harbour. Chennai Port, formerly known as Madras Port, is the second largest port of India, behind the Mumbai Port, and the largest port in the Bay of Bengal. Being the third oldest port among the 12 major ports of India, it is over 125 years old, although maritime trade started way back in 1639 on the sea shore. It is an artificial and allweather port with wet docks.