Review Question - QID 216842

A 16-year-old male running back presents to your clinic after a knee injury during his school's game yesterday. He states he attempted to spin to avoid a defender and his knee gave out, causing a loud pop. Immediate swelling was noted which is observed still today. Examination is difficult given acute pain and guarding but does not appear to demonstrate any varus/valgus laxity. His radiograph is seen in Figure A. Based on the most likely diagnosis, which of the following structures seen in Figure B is also injured in this patient?