A nurse is creating an activity plan for an older adult client. In the planning, the nurse considers the physiologic changes that may affect pulmonary function related to the normal aging process. Which of the following age-related physiologic changes should the nurse consider in the plan?

Choice A reason: Older adults have an increased risk, not decreased risk, for atelectasis due to reduced lung elasticity, weaker respiratory muscles, and decreased cough reflex. Choice B reason: Diaphragmatic movement decreases with age because of muscle weakening and changes in thoracic structure. Increased diaphragmatic movement is not an age-related change. Choice C reason: Chest wall compliance decreases with age due to calcification of costal cartilage and stiffening of the thoracic cage. Increased compliance is incorrect. Choice D reason: Decreased blood oxygenation is correct. Aging reduces alveolar surface area and capillary perfusion, leading to lower arterial oxygen levels. This physiologic change must be considered when planning activities to avoid hypoxemia and fatigue.