Final answer:
The key challenge corresponding to the Articles of Confederation is the representation in the national legislature, not the Declaration of Independence, which mainly emphasized broad ideals like life, liberty, and the pursuit of happiness.
Step-by-step explanation:
Representation in the national legislature—Articles of Confederation:
The direct answer to which item demonstrated key challenges posed in the corresponding document is c. Representation in the national legislature—Articles of Confederation.
The Articles of Confederation posed a significant challenge regarding representation in the national legislature. Each state had one vote in Congress, regardless of size, which led to disputes between larger and smaller states. Moreover, the Articles of Confederation did not allow for a centralized military, which made it difficult to defend the nation or pay its debts. In contrast, the Three-Fifths Compromise, mentioned in the Constitution, addressed the issue of how slaves were to be counted for purposes of representation and taxation, where every five enslaved individuals were considered equivalent to three free persons.
Regarding the legality of the slave trade and numeration of slaves for the purpose of representation, these issues were hotly debated during the Constitutional Convention and later addressed by the Three-Fifths Compromise and other constitutional provisions.