Vasco da Gama's voyage in 1497 was important because he found a trade route to India. Option C is correct.
Vasco da Gama was a Portuguese explorer and the first European to reach India by sea. His first voyage to India (1497–1499) constituted the connect to Europe and Asia by an ocean route, linking the Atlantic and the Indian oceans and therefore, the West and the Orient.
His discovery of the sea route to India was of paramount importance and opened the way for an age of global imperialism and for the Portuguese to establish a long-lasting colonial empire in Asia.