Why, a Few Years Before the Constitutional Convention Was Held

Why, a few years before the Constitutional Convention was held, had delegates from five states called on Congress to, at a later time, send commissioners to Philadelphia to make adjustments to the Articles of Confederation?

A) The country's elites had been shocked into action by Shays's Rebellion, in which an angry mob of farmers almost took over Massachusetts's state government offices.
B) Recent experience had shown that the national government was now strong enough to make the creation of a stronger central government an attainable goal.
C) The new nation's weak international position and domestic problems, linked to a weak central government, and radicals gaining control in some states as elites declined.
D) The Articles of Confederation, although working fairly well, had been hastily put together after the Revolution, and just needed updating.