Answer:
I think the answer is likely A
<span>Commensalism is an interaction in which one of those species would benefit, and the other one would not be affected. Parasitism is an interaction in which one of those species would benefit at the expense of the host organism. Thus, in commensalism we have one positive and one neutral result while in parasitism we have one positive and one negative result.</span>
It's called hypoxemia, it's low levels of oxygen in the blood, to be more specific, it's oxygen loss in your blood from your arteries. It can cause respiratory disorders, and tissue hypoxia, as a result of the blood not providing much oxygen to your body.
I hope I helped :)