Answer:
The correct answers are A, B, C and F.
Explanation:
A- Congress passes laws, but the President must sign them.
When Congress approves a law in both chambers, the bill goes to the President so that he signs it and in this way acquires operational validity. But it may happen that the President does not agree with the provisions of the law, due to political or ideological issues, and decides to veto it. That is, the President has the possibility of setting a limit to Congress through the veto, or giving a vote of confidence to this by signing the law.
B- The courts can declare laws unconstitutional.
In this case, if a judicial process reaches the Supreme Court of the United States, it has the possibility of checking the constitutionality of the law that is controversial, that is, verifying if there is a conflict between the law that is  applicable to the case and the Constitution of the United States. If there is a conflict, the Court may determine the unconstitutionality of the law, thereby exercising control over the Congress.
C- The President appoints, but Congress approves judges.
The President has the power to appoint the judges of the federal judicial system, as well as the members of his cabinet. But these appointments are subject to the approval or not by the Supreme Court, which in this way exercises control over the powers of the President.
F- Congress can impeach the President
Through Impeachment, Congress has the power to control the actions of the President, prosecuting him if it considers that he committed an illegal act during his time in office.
