Cite evidence to show that the executive office of the president is an essential part if the executive branch

The President is essential to the Executive branch because this is the office that is responsible for putting laws into effect. Without this office, legislation passed by Congress would not have a second office to approve of the documents, and could lead to abuses of power. In addition, the office of President is the head of the military forces, and is thereby the first port-of-call for high-level decisions: otherwise, all these decisions would be made by lower-ranking officers and could lead to disagreements.

The answer is protestant reformation.