Which of the following groups would contain the largest number of organisms?
А. class
B. order
C. phylum
D. family

А.class

Explanation:

Depending on the questions answers you'd go by the order of the groups. Domain (1st largest), Kingdom(2nd largest), Phylum(3rd largest), Class(4th largest), Order(5th largest), Family(6th largest), Genus(7th largest), Species(last largest).

what's the rest of the question

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.