Port on Zuari Estuary
The correct answer for the port located on the Zuari Estuary is option 'A' - Marmagao. Let's explore the details behind this answer.

Port of Marmagao:
The port of Marmagao is situated on the coast of Goa, India, and is one of the major ports in the country. It is located on the southern bank of the Zuari Estuary, making it an ideal location for maritime activities.

Importance of Zuari Estuary:
The Zuari Estuary is a significant water body formed by the confluence of two rivers, the Mandovi and the Zuari. It serves as an important channel for transportation and trade, with the port of Marmagao being a vital link in this network.

Factors contributing to Marmagao's prominence:

1. Strategic Location:
Marmagao's location on the Zuari Estuary provides it with several advantages. It has easy access to the Arabian Sea, making it a favorable port for both domestic and international trade. The estuary also provides a natural harbor, making it ideal for docking and loading/unloading of cargo ships.

2. Connectivity:
Marmagao port is well-connected to various parts of India through a network of railways, roadways, and airways. This connectivity facilitates the transportation of goods to and from the port, ensuring smooth trade operations.

3. Trade and Cargo Handling:
Marmagao handles a diverse range of cargoes, including iron ore, coal, petroleum products, machinery, and general cargo. It plays a crucial role in the export of iron ore, which is mined in the nearby regions of Goa. The port has modern facilities and infrastructure to handle large volumes of cargo efficiently.

4. Economic Significance:
The port of Marmagao contributes significantly to the economy of Goa and India as a whole. It generates employment opportunities for the local population and contributes to foreign exchange earnings through trade activities. The port also supports the growth of various industries and businesses in the region.

In conclusion, the port of Marmagao is located on the Zuari Estuary and serves as a crucial hub for maritime trade and transportation. Its strategic location, connectivity, and efficient cargo handling facilities make it a prominent port in India.