B makes the most sense to me so I would go with that
"Bad" bacteria because there are also good bacteria that we need in order to live not just healthy, because every person gets sick and we need it for our body. Too much good thing is a bad thing.
Aerobic exercise is physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process. Examples would be cycling, running, swimming, jogging, etc.
You call for help and lay them on their left side and make sure their breathing