Question

the supreme court can order the president to enforce a law. which arrow on the diagram stands for this check on executive power?

Explanation:

The problem is about the system of checks and balances in the US government, specifically the judicial (Supreme Court) checking the executive (president). In the diagram, the arrow from the Judicial (Supreme Court) to the Executive represents this check, as the Supreme Court (judicial branch) ordering the president (executive branch) to enforce a law is a judicial check on executive power.

Answer:

The arrow from the "Judicial" circle to the "Executive" circle.