Answer:
Facultative mean survival in presence or absence of oxygen;
Obligate mean survival either in the presence of oxygen or absence, NOT BOTH
Explanation:
An obligate aerobe is an organism capable of survival ONLY in the presence of oxygen. A good example is human being.
A facultative anaerobe is an organism capable of survival in either the presence of oxygen or absence. A good example is Escherichia coli
Obligate anaerobes is capable of survival ONLY in the absence of Oxygen, because they die in the presence of oxygen.
There is an abundance of said species!
It is B I think
Hope this helped