What was ended by Ferdinand and Isabella's conquest of the Kingdom of Grenada? Muslim influence in Spain

Interest in world exploration

Religious tolerance in Spain

English influence in Grenada

Out of the four choices, Muslim influence in Spain is the correct answer.

Not interest in world exploration - this was an internal conflict in Spain

Not religious tolerance in Spain - Ferdinand and Isabella were known as the Catholic Monarchs and were highly religiously tolerant (of their religion, of course).

Not English influence in Granada - Granada was a Muslim emirate.