What Major Political Change Was Made by the Founder of the Song

What major political change was made by the founder of the Song dynasty?

A) All high military officials were executed or exiled.
B) Political power was put into the hands of the civilian bureaucrats rather than the military generals.
C) He took complete control of the military.
D) Admiring the power of the Qin, he made himself sole leader of the government.
E) Military governors were replaced by members of the royal court.