This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
Which type of motor unit is of prime impoance in generating the muscle power necessary for the maintenance of posture? 
Select and explain. 
A. Low threshold, fatigue-resistant, B. High threshold, fatigable, C. Intrafusal, gamma controlled, D. High threshold, high force
A: Low threshold, fatigue-resistant
Answer: A: Low threshold, fatigue-resistant 
Explanation: The low threshold for activation, fatigue-resistant motor units are the type active in postural control. Intrafusal muscle fibers do not contribute to force generation.