3. The Middle Ages refers to A. The dark period of time between Egypt and Mesopotamia
B. The period in Europe that saw the Black Death
C. The era of cathedral building
D. Both B and C

D. Both B and D

Explanation:

The 'Middle Ages' are called this because it is the time between the fall of Imperial Rome and the beginning of the Early modern Europe. The Dark Ages are given this name because Europe was in disarray in comparison to the orderliness of classical antiquity and life was short and poor.

hope i helped

bujías y una hora antes y no me parece muy difícil