Explanations:The concept of subsidiary ports is important in understanding the logistics and maritime infrastructure of a region. A subsidiary port is a smaller port that supports the operations of a larger, more central port. In the context of West Bengal, Kolkata is a major port city that handles a significant amount of maritime traffic and cargo. To manage this traffic more efficiently, subsidiary ports have been developed to distribute the workload and provide additional facilities for handling cargo.
Haldia, located on the Hugli River, is one such subsidiary port that supports Kolkata's port operations. The Hugli River is a distributary of the Ganges River, and it flows through West Bengal, providing a natural waterway for maritime traffic. Haldia was developed to alleviate the congestion at the Kolkata port and to provide additional facilities for cargo handling, shipbuilding, and other maritime activities.
The other options provided in the question are not subsidiary ports of Kolkata. Tuticorin is a major port located in Tamil Nadu, which is a different state in southern India. Visakhapatnam is a major port located in Andhra Pradesh, another state in southern India. Jawaharlal Nehru is a name and not a port, so it is not relevant to the question.
Understanding the geographical location and the role of subsidiary ports is crucial for answering questions related to port operations and logistics. Haldia, being a subsidiary port of Kolkata, plays a significant role in the maritime infrastructure of West Bengal and supports the economic activities of the region.