This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
You are testing knee jerk reflex in a patient. The afferents in deep tendon reflexes are carried by: 
Select and explain. 
A. Dynamic intrafusal fibers, B. Golgi tendon organ, C. Nuclear bag and static chain fibers, D. Both Golgi tendon and muscle spindle
A: Dynamic intrafusal fibers
Answer: A: Dynamic intrafusal fibers 
Explanation: Ans. a. Dynamic intrafusal fibers