Final answer:
The taxa immediately following phylum in the classification hierarchy is class, making A) Order the correct answer to the student's question.
Step-by-step explanation:
When classifying organisms from broad to narrow, the taxa that immediately follows phylum is class. Therefore, to answer the student's question:
The correct answer to the given question is A) Order.
The Linnaean system, proposed by Carl Linnaeus in the 18th century, includes the following hierarchical structure: domain, kingdom, phylum, class, order, family, genus, and species. In this system, each level represents a more narrowed down classification, grouping organisms based on shared characteristics. The level of order comes right after class when moving from a broader classification to a more specific one. For instance, in the domain Bacteria, Proteobacteria would be classified at the phylum level. Linnaeus's contribution is essential to our understanding of biological classification and taxonomy today.