The correct answer to this open question is the following.
Explain why early European explorers and rulers might have decided to take the dangerous journey across the Atlantic to claim land and colonize North America.
In a time of European superpowers during the Middle Age, European monarchies wanted to acquire more land and territories to strengthen their power and dominion. That is why the Kings supported explorations and navigations expeditions to find more or better routes to Africa and the Indies. Portugal had a great navy for the time. Spanish also had a good navy and hired the best navigators to lead the expeditions.
For instance, that was the case of Christopher Columbus, who received the sponsorship of Ferdinand of Aragon and Isabelle del Castille -King and Queen of Spain- to explorer a shorter route to the Indies. That is how he arrived in the Americas on October 12, 1492.