The stress? Bad eating habits due to lack of money and time? There could be lots of reasons but that's what came to mind first.
you should drink a full glass of water or take it on an empty stomach preferably you can eat applesauce but avoid drinking milk.
it can cause an irritation in your throat.
The answer to your question is B. CDC
I would say A because when swimming too fast that can cause cramps and that can cause you to drown some times
