The Europeans traveled across the Mediterranean Sea to search the Silk Road to A) obtain clothes, spices, and other goods. They were not necessarily interested in ancient religious sites, they were not escaping natural disasters at home, and to a degree they were searching for new opportunities, but the better answer is A.
Social classes: King
Priests
Scribes
Merchants & Artisans
Commoners
Slaves
Economic classes: calendar and irrigations (via canals and ditches), craftsmen (copper and bronze workers)
