Answer:
A. William Howard Taft
Explanation:
He is the only President ever to do this.
~Hello there! ^_^
your question: Which official is the most powerful member of the White House..?
Your answer: The Chief of staff is the official that is the most powerful member of the White House. This person guides the White House staff.
~Hope this helps! :D
it was marked by a great degree of cooperation and was essential to securing the defeat of Nazi Germany