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.
The correct answer is option C, For more kingdoms were introduced
Linnaeus was the first to develop a system of classification of living things. He mainly grouped the living things into animal or plant kingdom, but later with the advent of microscope it became easy for the researchers to observe microscopic beings and thus three new kingdoms were proposed namely- fungi, protists (considered as simple organism) and monera (bacteria).
Not only this with in a kingdoms comes several phylum, these phylums were also reorganized and recategorised based on the discovery of more categories and subcategories.