It would be the "B. The Secret Service" that does not operate under the Department of the Treasury, sine the primary goal of the Secret Service is to protect the President.
I’m guessing a sewage system
Answer:
I think it's supervising contracts between freed people and their employers
The Freedmen's Bureau provided food, housing and medical aid, established schools and offered legal assistance. It also attempted to settle former slaves on land confiscated or abandoned during the war.
