The correct answer should be<span> D) conserving natural resources without harming the environment
Instead of using new resources, you can use the waste from previous production and recycle it for the sake of creating something else, which preserves the resoruces and doesn't harm the environment.</span>
Answer:
The function of the pleura is to allow optimal expansion and contraction of the lungs during breathing. The pleural fluid acts as a lubricant, allowing the parietal and visceral pleura to glide over each other friction free. This fluid is produced by the pleural layers themselves.