The correct answer is: D. Revise the Articles of Confederation.
Step-by-step explanation:
The Philadelphia Convention, also known as the Constitutional Convention, took place in the Old Pennsylvania State House in 1787. It had as main purpose to revise the Articles of Confederation, which were an initial agreement between the 13 states after obtaining freedom from Great Britain.
The Articles of Confederation were the first form of Constitution of the United States, and they focused on mantaining freedom and sovereignity for the states, united by an extremely limited central government.
Members of the Philadelphia Convention knew how weak the central government was, and that it could not mantain the order and balance between the states, so they decided to replace it with the Constititution, so they could achieve a stronger federal government while the states remained free and sovereign.