Defeat at the Hands of Napoleon Prompted the Prussian Monarchy

Defeat at the hands of Napoleon prompted the Prussian monarchy to

A) create parliamentary institutions to gain support of the people.
B) challenge the Junkers' control of their estates.
C) open some positions in the bureaucracy and the military to non-nobles.
D) abolish the military reserve in favor of a larger full-time army.
E) implement a constitutional system.