Answer:
President, executive departments, individual federal agencies (D)
Step-by-step explanation:
It's not (A) because congress is part of the legislative branch of government. Also, the judicial branch of government is separate from that of the executive.
It's not (B) because the senate is part of the legislative branch of government. Also, the legislature is separate from that of the executive branch.
It's not (C) because the supreme court is part of the judicial branch of government. Also, congress is part of the legislative branch of government, which is separate from that of the executive.
However, it is (D) because the president, executive department, and individual federal agencies are all part of the executive branch of government.