Why can guessing before seeing an answer help, even when the guess is wrong?

Answer: A guess gives you an expectation to compare with the correct answer.

A wrong answer strengthens memory by being stored as correct. — Storing a wrong answer as correct would teach the wrong thing, not explain better memory for the real answer. The useful situation includes seeing the correction after the guess. The guess can help prepare you to notice that correction; leaving it uncorrected is a different situation.

Repeating the question explains the benefit without using the feedback. — Repeating the question alone does not explain the extra benefit of trying to answer before receiving feedback. Attempting an answer creates an expectation that simply rereading need not create. The later comparison with the correct answer is what this option leaves out.

A guess gives you an expectation to compare with the correct answer. ✓ — A guess gives the correct answer something to be compared against. When feedback arrives, you can notice the gap between what you expected and what was right, which can make the correction more memorable. This is a benefit of guessing followed by feedback, not a reason to practice errors without correction.