Question

what accurately describes the relationship between the principle of "separation of powers" and the Articles of Confederation

Answer 1

"Separation of powers" is checks and balances. There are three powers within the US government: the judicial (courts), legislative (congress, senate, and house of representatives), and executive (President). One cannot be over the other.
The Articles of Confederation is the Constitution of the original 13 colonies. It starts with "We the People . . . "
I hope this helps!