Mark turned quickly, pivoting on his right foot, while he was playing basketball. he felt a sudden, sharp pain in his knee and found his leg would not support him well. when he tried to walk off the court, his knee wobbled sideways. based on this evidence, which of the following has he most likely injured? a) he has broken the femur and it can no longer maintain proper muscle tension to support his weight b) he has injured the quadriceps muscle that is responsible for moving his leg up and down as he walks or runs. c) he has injured one of the tendons or ligaments that keep his knee in place, connecting it to the surrounding muscle and bone. d) he has torn the cartilage that cushions the interior of his knee, keeping it aligned with the bones in his leg.