Explanations:The concept of subsidiary ports is crucial in understanding the logistics and infrastructure development in major port cities. In the context of West Bengal, the Kolkata port has historically been a significant maritime gateway for the region. However, as the volume of maritime traffic increased, the Kolkata port faced congestion and logistical challenges. To address these issues, a subsidiary port was developed to handle some of the traffic and provide additional facilities for cargo handling.
Haldia, located on the Haldia dock system, which is part of the Hooghly River, was developed as a subsidiary port to the Kolkata port. The Haldia dock system is strategically positioned to serve as a major cargo handling facility, thereby reducing the pressure on the Kolkata port. The development of Haldia as a subsidiary port was a strategic decision to enhance the overall efficiency of the port system in the region.
It is important to note that subsidiary ports are not just smaller versions of the main port but are designed to complement the main port by handling specific types of cargo or providing specialized services. In the case of Haldia, it was developed to handle the increasing maritime traffic and to provide better facilities for cargo handling, thus relieving the congestion at the Kolkata port.
Other options such as Kochi, Kandia, and Vishakhapatnam are not relevant to the context of West Bengal and the Kolkata port. Kochi is a major port in Kerala, Vishakhapatnam is a major port in Andhra Pradesh, and Kandia is not a recognized port in India. Therefore, Haldia is the correct answer as it is the subsidiary port developed to relieve the growing pressure on the Kolkata port.