What Was the Reason Charlemagne Issued the Missi Dominici

What was the reason Charlemagne issued the missi dominici ?

A) To create the position of comes to represent the king.
B) To appoint clergy to convert the Germanic tribes to Christianity.
C) To establish a palace school to train government officials as well as the clergy.
D) To establish a line of succession for the Holy Roman Empire.
E) To establish special officers who reported directly to the king about the conduct of counts and others.