Answer:
D. The search for more sources of wealth and trade
Step-by-step explanation:
In the 1400s, European empires competed with one another in order to be the supreme power in the world. In order to achieve that, most of them realize that they need to increase their economic power.
This prompted many empires to invest in explorations in order to seek potential slave labors and cheap resources from smaller /weaker countries. They planned to accumulate the resources and sell it in higher price in order to improve their nations' wealth. These explorations marked the beginning of the Age of Discovery.