The correct answers are:
- The Turks captured Constantinople, closing the path to the Silk Road;
With the Ottoman Turks coming on the scene and capturing Constantinople and large portions of the Middle East, the route for the Silk Road was closed to the Europeans, and also the waters were very dangerous for travel and trade in the eastern part of the Mediterranean. That resulted into investing into finding new routes for free trade by their own terms.
- Europeans developed the economic system of mercantilism and needed reserves of gold and silver;
The mercantilism was adopted by the European colonial powers, and this economic system was suggesting that the amount of natural reserves in the world is static, so the Europeans rushed to explore and colonize as much as they could, in order to get hands of as much gold and silver as possible.