Which classification is the second highest taxonomic rank below domain?

The second highest taxonomic rank below the domain is indeed the kingdom. In biological classification, the hierarchy starts with the most inclusive category, which is the domain, and then narrows down through various ranks. Following the domain, the next step down in this hierarchy is the kingdom.

For example, in the three-domain system, the domains are Bacteria, Archaea, and Eukarya. Within the Eukarya domain, you can find kingdoms such as Animalia, Plantae, and Fungi. This hierarchical structure reflects the evolutionary relationships between different organisms and helps scientists categorize and study biodiversity more effectively.

Other ranks such as class, phylum, and family are located further down the hierarchy; class is a subdivision within phylum, phylum is a division under kingdom, and family is a subgroup of genus. Therefore, among the options provided, kingdom is correctly identified as the second highest taxonomic rank below domain.