The crusade played a key role in exchanging cultures between Christians and Muslims. Muslims were much more advanced in medicines and science, which interested Europeans to travel to their land to gain knowledge. Some of the classical philosophy and arts studies by scholars. The Italian city-states began to flourish because of the growing trade connection with the Muslim because it brought many goods. As the trading connection increase, it led to the rise of the renaissance.
Just by common sense we can rule out both C and B because neither of those make sense for this case. High population really doesn’t matter. So the most logical answer is D. Mostly Defending Familiar Territory
