Answer: The bacteria uses the oxygen present in the mouth.
Explanation:
The plaque that is formed in the teeth is a highly anaerobic bacteria but it can sustain in the environment rich in oxygen. The oxygen is used by the bacteria and there is a absence of oxygen in the teeth.
It is formed in between the teeth which needs oxygen to survive and if remains for tooth for a longer period of time then it began to grow without oxygen.
It basically uses the oxygen available in the mouth and makes the condition anaerobic.
Things such as coal and oil are limited because they are only found in some places
Mutations (changes) to the DNA within the cells.
Answer b is the best example
Coordination because with out that u can't do anything