One of the Founding Principles of Our Government Is Separation

One of the founding principles of our government is separation of powers.How do administrative agencies tend to conform to,or violate this principle?

A) They raise concerns related to this principle because they perform all three functions of government.
B) They tend to conform to this principle because most commissioners or board members are appointed by the President.
C) They tend to conform to this principle because they only follow the law,and do not make any law.
D) They tend to violate this principle because they are created by Congress through passing of enabling legislations.