Question

congress can investigate, or look into, the president and his or her staff. which arrow on the diagram stands for this check on executive power?

Explanation:

Congress is part of the legislative branch. The check on the executive power by Congress is shown by an arrow from the legislative - "Legislative" to the executive - "Executive" in the diagram representing the system of checks and balances.

Answer:

The arrow pointing from the "Legislative" circle to the "Executive" circle.