Which of these terms is often used to describe europe during the postclassical period?
a. eurasian period
b. middle ages
c. islamic caliphate
d. song dynasty

The post-classical period in western Europe is the period that began immediately after the end of the Roman Empire (the classical period) and is most often called the Middle Ages or the Medieval Ages. 
The answer is letter B. 
>> Medieval Ages is used instead of the Middle Ages by some scholars because they believe this makes the time period sound trivial and inconsequential if compared with the classical period and Renaissance period.

Ummm they were radical