Complete the sentence. the early middle ages in europe (500-1000 a. d.) are often called the dark ages because
a. there are no written records from the period
b. literacy and education declined
c. all government disappeared
d. the muslims conquered all of italy and gaul

The correct option is A. Dark age are so called because compare to other eras, historian don't know much about this era. This period of time is considered lost to history, no important record about the era has survived, The cause of the dark ages was the collapse of the Roman Empire and the invasions and raiding that characterized it.