In my opinion the best sounding answer is C I hope this helpes<span />
I found the attached image on the internet related to this question.
The solid arrows represent neuronal communication. The stimulus, the effects, and the flow of information is all done by receptors and synapses that send a signals across the body in order to have effective feedback responses promoting the homeostasis of the organism.
I believe that it's an exhausted bear. Cellular respiration is the way plants and animals receive energy. If the bear is exhausted, it means it's cellular respiration is lacking.
The answer is (A) as <span> increasing risk of lung cancer is from increasing levels of exposure to outdoor air pollution and </span>particulate matter