After Fifty Years of Civil War in the Third Century

After fifty years of civil war in the third century, the emperors of the reunified empire

A) made taxation more efficient by sending imperial tax collectors to replace local elites.
B) asserted their autocracy aggressively, through harsh laws and punishments.
C) signed a truce with the tribes on the frontiers of the empire.
D) required that Christianity be universally practiced as the new state religion.