The correct answer is option 4, Portugal. Portugal was the first nation to start sea-trade with India. During the 15th and 16th centuries, Portuguese explorers, led by Vasco da Gama, successfully navigated the Cape of Good Hope and reached India by sea. This opened up a new trade route from Europe to India, bypassing the overland trade routes that were controlled by the Ottoman Empire.

Portugal`s entry into the Indian Ocean trade had significant consequences for the region. They established various trading posts along the coasts of India, including Goa, Cochin, and Calicut. Portuguese traders brought back valuable commodities such as spices, cotton, and silk from India to Europe.

It is important to note that while England, France, and the Netherlands also became involved in sea-trade with India during the Age of Exploration, Portugal was the first to initiate this trade relationship.