Which of the following positions is typically considered part of the President's Cabinet?

The Secretary of Defense is typically considered part of the President's Cabinet because the Cabinet is composed of the heads of the executive departments and other key advisors to the President. The Secretary of Defense leads the Department of Defense, overseeing military policy and operations, which positions this role as a principal advisor to the President on matters of national security and defense.

In contrast, the Chief Justice of the Supreme Court is not part of the Cabinet; instead, the Chief Justice leads the judicial branch of government. The Ambassador to the United Nations, while an important diplomatic role, is not a Cabinet position but is considered a key advisor in foreign policy matters. Similarly, the Chair of the Federal Reserve heads the central banking system of the United States and has significant influence over economic policy, but this position is independent of the executive branch and does not serve as a Cabinet member.