Which of these groups is the smallest level of classification

A. Phylum

B. Family

C. Order

D. Genus

D. Genus

Explanation:

This is the smallest classification level because of all those named it is the one that covers the least organisms. This taxonomic level is between the level of species and family, that is, it covers only several related species. In order from largest to smallest the levels of organization are domain, kingdom, phylum, class, order, family, gender and species

Answer: Number D. Genus