The correct answer is Kochi.

Kochi, a major port city on the Malabar Coast of Kerala, India, is known as the "Queen of the Arabian Sea". This title reflects its rich history as a significant trading center, its strategic location, and its natural harbor, which is one of the finest natural harbors in the world. Its geographical position and historical importance have contributed to Kochi's prominence in maritime trade and commerce for centuries. Many historical factors, including its role as a spice trading hub, its strategic value, and the beauty of its natural harbor, have led to this title. The city's enduring legacy and continued significance in maritime activity solidify its claim to this prestigious moniker.

While other ports like Mumbai, New Mangalore, and Mormugao are also important, they don't hold the same historical and geographical significance as Kochi, which is uniquely suited to the title "Queen of the Arabian Sea" due to its natural attributes and historical impact on the region's trade and cultural development. The other options are notable ports, but they lack the historical and geographical context to justify this particular title.