Final answer:
The delegates at the Constitutional Convention came up with the idea of a single executive for the Executive Branch, which eventually became the role of the president in the United States.
Step-by-step explanation:
The delegates at the Constitutional Convention came up with the idea of a single executive for the Executive Branch. They debated various forms and models for the role, including an elected monarchy and a governing council. Ultimately, they settled on the concept of a single elected executive, with the expectation that George Washington would become the first president. This idea of a single executive, elected by the people, has remained a fundamental aspect of the Executive Branch in the United States.