The various taxonomic levels (namely, genera, classes, etc.) of ...

[geoffrey]

The various taxonomic levels (namely, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of
A) how widely the organisms assigned to each are distributed throughout the environment.
B) their inclusiveness.
C) the relative genome sizes of the organisms assigned to each.
D) morphological characters that are applicable to all organisms.

[penguins]

Easy! It's B. Bye for now

[geoffrey]

Thanks so much, the answer you provide was right on!