Final answer:
The functional change in the pulmonary system that includes decreased elastic recoil is correctly identified as D) Decreased Elastic Recoil, which is a change that reduces lung compliance, making breathing more difficult and reducing gas exchange efficiency.
Step-by-step explanation:
The functional changes in the pulmonary system described are associated with aging or various lung diseases. Among the options presented, decreased elastic recoil accurately reflects a change in the lung's natural elasticity, which typically diminishes over time or with conditions such as fibrosis, leading to difficulty in breathing and reduced lung function.
Reduced elastic recoil impairs the lungs' ability to expand and contract effectively during breathing. This alteration in lung compliance contributes to a variety of issues, including decreased gas exchange due to the stiffening of lung tissues and the collapse of airways upon exhalation.
In conclusion, the correct answer is D) Decreased Elastic Recoil. This decrease in elastic recoil can lead to an increase in residual volume, as the lungs cannot expel as much air, and a decrease in gas exchange efficiency, directly affecting overall respiratory function.