Rulers of European nations wanted to explore the seas because

they wanted to find out if the world was really flat.

they wanted to earn money from the fishing industry.

they heard there were sea monsters in the oceans.

they wanted to try out the new ships called Caravels.

they wanted to find a trade route to Asia.

Question

Rulers of European nations wanted to explore the seas because
 
   
they wanted to find out if the world was really flat.
 
   
they wanted to earn money from the fishing industry.
 
   
they heard there were sea monsters in the oceans.
 
   
they wanted to try out the new ships called Caravels.
 
   
they wanted to find a trade route to Asia.

baconboy73 · Answer

They wanted to find a trade route to Asia.  The traditional route to Asia was long: they had to travel along almost the entire coast of Africa to reach Asia, so exploration was done to hopefully find a faster way to get there.