The correct answer is option 2, Lothal. Lothal is the port-town of the Indus Valley Civilization. It is located in present-day Gujarat, India, and was one of the major cities of the ancient civilization. Lothal was a significant trading center, and its proximity to the Sabarmati River and the Gulf of Khambhat made it an important maritime hub. The excavation of Lothal has revealed a well-planned city with advanced urban infrastructure, including a dockyard, warehouses, and a marketplace. The discovery of seals, beads, pottery, and other artifacts at Lothal suggests extensive trade connections with other regions in the ancient world. The port of Lothal played a crucial role in establishing maritime trade links during the Indus Valley Civilization.