Respuesta :
the correct answer is choice A because when you breath in, bacteria enters your mouth and it allows them to reproduce. also since your mouth is dark and damp, it is a good source of nutrition.
The correct answer is A. Other bacteria actually protect our teeth and gums. There are some bacteria, however, that we'd rather do without, since they cause tooth decay and gum disease. Streptococcus mutans is the bacteria you've probably heard the most about. It lives in your mouth and feeds on the sugars and starches that you eat.