Final answer:
The best diagram would illustrate Enlightenment ideas such as popular sovereignty, separation of powers, or checks and balances, all of which influenced the framers of the U.S. Constitution and are reflected in its articles.
Step-by-step explanation:
The diagram that best shows how an Enlightenment idea influenced the U.S. Constitution would be the one that illustrates concepts such as the Social Contract, popular sovereignty, separation of powers, or checks and balances. These ideas stem from influential Enlightenment thinkers like John Locke and Montesquieu, who advocated for a government structured by the consent of the governed, with a separation of powers to prevent tyranny.
The U.S. Constitution embodies these Enlightenment ideals, especially in its first three articles, which establish a federal government composed of three branches—legislative, executive, and judicial. The Constitution also begins with "We the People," reflecting the Enlightenment concept of popular sovereignty. Moreover, the system of checks and balances that the Constitution promotes is directly taken from Montesquieu's Enlightenment thought on how to best structure a government.
Therefore, without having the specific diagrams (A-D) to evaluate, it can be stated that the best diagram would be one that reflects these Enlightenment influences on the framers of the Constitution and the governmental structure they created.