Select the correct answer. Which quotation from the United States Constitution includes an example of separation of powers?

A.
“The President . . . may require the Opinion, in writing, of the principal Officer in each of the executive Departments . . .”
B.
“No State shall, without the Consent of the Congress, lay any Imposts or Duties on Imports or Exports . . .”
C.
“Every Bill which shall have passed the House of Representatives and the Senate, shall, before it become a Law, be presented to the President of the United States . . .”
D.
“No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court.”