In aging, the diaphragm's function compared to accessory muscles is

• A. Diaphragm remains unchanged
• B. Diaphragm weakens
• C. Diaphragm strengthens
• D. Diaphragm becomes rigid

Answer: (A)

The key idea is that the diaphragm stays the main driver of breathing even as we age, while the chest wall becomes stiffer and the body relies more on accessory muscles to help with ventilation. The diaphragm is highly fatigue-resistant and maintains its inspiratory role, so its overall function is preserved compared with younger adults. Older adults often recruit neck and chest wall muscles to assist breathing, but this doesn’t mean the diaphragm weakens; it simply means the work of breathing shifts toward additional muscles. Therefore, saying the diaphragm remains unchanged best fits what happens with aging. Options suggesting the diaphragm weakens, strengthens, or becomes rigid don’t match typical aging patterns, where changes are more about chest wall compliance and use of accessory muscles rather than the fundamental diaphragmatic function.