In most cases, what is the lowest major division in the classification system of insects?

• A. Species
• B. Phylum
• C. Order
• D. Class

Answer: (A)

Taxonomic classification is arranged from broad to narrow, and the smallest major division used to name a distinct group is species. Insects follow this pattern: there are higher ranks like phylum (Arthropoda) and class (Insecta), then order, and further down to family, genus, and finally species. The idea is that a species represents a group of individuals that can interbreed and produce fertile offspring under natural conditions, making them a reproductively coherent unit. Subdivisions within a species, such as subspecies, can exist, but they don’t constitute a separate major rank in the standard hierarchy. The other options—phylum, class, and order—are broader categories that encompass many different groups, not the smallest unit.