Final answer:
Dead space air is the term used for air within the respiratory system that is not involved in alveolar gas exchange, encompassing both anatomical and alveolar dead space.Answer is option (d).
Step-by-step explanation:
In the context of alveolar gas exchange, the air that is not involved in gas exchange is referred to as dead space air.
This includes both the anatomical dead space, which is the air present in the respiratory passages that never reaches the alveoli, and alveolar dead space, which is the air in alveoli unable to participate in gas exchange due to disease or abnormal blood flow. Therefore, the correct answer to the question is D. Dead space air.