Concept:The animal kingdom contains many groups, but the class with the greatest number of species is the insects.
Explanation:Insects belong to the phylum Arthropoda, which is the largest phylum in the animal kingdom.
Within Arthropoda, the class Insecta is the most abundant, making up about
70% of all known animal species.
This is far more than mammals, birds, or annelids.
Therefore, the most abundant group among the options is Insecta.
Answer:C. Insecta