An honest C you earned teaches you more than a borrowed A.

A grade only tells you something if it came from you. A C you earned maps exactly where your understanding runs out, and that map is usable. An A that came from someone else’s work tells you nothing except that you got through the week. The number looks better and the knowledge is thinner.

Pick the last assignment where you leaned on help you did not understand, and redo one problem from it alone. That stuck point is the actual lesson the grade was supposed to give you.