This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Anatomy
[{'content': 'Which muscle tendon is stretched in patellar tendon reflex? \nSelect and explain. \nA. Biceps femoris, B. Quadriceps femoris, C. Adductor magnus, D. Quadratus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Quadriceps femoris stretches in patellar tendon reflex. Striking of the patellar tendon with a reflex hammer just below the patella stretches the muscle spindle in the quadriceps muscle.', 'role': 'assistant'}]