Who is the commander in chief mentioned in the text?

The correct answer is tied to the position of the Commander in Chief of the Armed Forces, which is a role designated to the President of the United States by the Constitution. The Honorable Donald J. Trump, who served as the 45th President from January 20, 2017, to January 20, 2021, held this title during his presidency. As Commander in Chief, the President has ultimate authority over the military and is responsible for national defense, making decisions that affect the U.S. armed forces.

The other individuals listed held or currently hold significant positions but do not serve as Commander in Chief. James Mattis was the Secretary of Defense, Richard Spencer was the Secretary of the Navy, and Mike Pence was the Vice President. Each of these roles plays a critical part in the leadership of the military and national governance, but they do not have the same constitutional authority as the President regarding military commands and operations.