What Motivated the Portuguese to Begin Exploration to Find a Water

What motivated the Portuguese to begin exploration to find a water route to India, China, and the East Indies?

A) To prove that the world was round.
B) To spread the Protestant faith.
C) To establish land empires in India and China.
D) To eliminate the Muslim "middlemen" in the luxury goods trade.
E) To find markets for Portugal's surplus manufactured goods.