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: Physiology
The maintenance of posture in a normal adult human being depends upon: 
Select and explain. 
A. Integrity of reflex arc, B. Muscle power, C. Type of muscle fibers, D. Joint movements in physiological range
A: Integrity of reflex arc
Answer: A: Integrity of reflex arc 
Explanation: A i.e. Integrity of Reflex arc'Postural Reflexes not only maintain the body in an upright balanced position but also provide the constant adjustments necessary to maintain a stable postural background for voluntary activity'- Ganong 22"V207Integrity of the postural reflex arc is therefore the single best answer of choice.