The role of the president has evolved over time because the needs of the nation have changed.
the role of the executive branch has changed.
the role of Congress has changed.
the needs of the chief of staff have changed.

It should be noted that the role of the president has evolved over time because the needs of the nation have changed.

The President serves as the head of government as well as  Commander-in-Chief of the armed forces in a country.

However, some roles can change as the country is developing and as the Constitution is been amended.

Therefore, option A is correct because, the needs of the nation can changed which change role of the president.

Learn more about role of the president at;

link

the needs of the nation have changed.

Explanation:

The role of the president has evolved over time because the the needs of the nation have changed.

The needs of the nations have changed with time and the President being responsible for the well-being of the nation had to also adjust his roles also to meet the growing needs and demands of the populace.

the answer is selfishly. hope this !