Hi can you help me out with this question the answer choices "becomes shorter" and "becomes longer" are wrong so which one of the other two would be correct?

Question 7 Which of the following describes the moment arm of the biceps? Selected Answer: The moment arm of the biceps becomes longer as the elbow is flexed past 90 degrees Answers: The moment arm of the biceps is at its longest when the elbow is flexed 90 degrees The moment arm of the biceps becomes longer as the elbow is flexed past 90 degrees The moment arm of the biceps becomes shorter as the elbow is flexed past 90 degrees The moment arm of the biceps does not change based on the elbow flexion angle