Answer:
B. Those who did well under the previous leader become enemies.
C. The introduction of new rules and methods is hard for people to take.
D. Those who may do well under the new prince are weak defenders.
E. It is dangerous to take the lead in the introduction of a new order.
Explanation:
The statements that expresses the idea that acquiring a principality can be difficult are in options B, C, D, and E.
In his practical guide titled 'The Prince', Niccolo Machiavelli, outlines the practical tips of maintaining political power. In his practical political guide, Machiavelli outlines the difficulties of acquring and maintaing power which are enlisted in options B,C,D, and E.
Thus option B, C, D,and E are correct answers.