Final answer:
The power specifically given to the president by the U.S. Constitution is to command the army, alongside the authority to nominate officials and negotiate treaties with Senate approval. The correct answer is option d.
Step-by-step explanation:
The power specifically given to the president by the U.S. Constitution is to command the army as the commander-in-chief. The president also holds the authority to nominate executive officials, ambassadors, and federal judges, subject to the consent of the Senate. Additionally, the president may negotiate and sign treaties, which must be ratified by the Senate.
While Congress retains the power to tax and spend, declare war, and pass legislation, the president has significant influence in foreign policy and acts as the chief diplomat, representing the United States globally.