The correct answer is C) Diplopoda.
Diplopoda, commonly known as millipedes, are the arthropods that possess the most legs as adults. While the name ‘millipede’ implies that these creatures have a thousand legs, the reality is that they typically have between 34 to over 400 legs, depending on the species. They have two pairs of legs per body segment, which contributes to their high leg count.
In comparison, Chilopoda, known as centipedes, have only one pair of legs per segment, resulting in fewer legs overall. Crustacea, such as crabs and lobsters, also have a considerable number of legs, but most species do not surpass the total number found in Diplopoda. Insects, while incredibly diverse, generally have six legs as adults, which is consistent across all species in Class Insecta.
This distinctive feature of Diplopoda makes them unique within the arthropod phylum, showcasing the vast variety that exists within this group of invertebrates.