Identifying arthropod by leg count and body segments

Steps:

• Examine the number of legs: many pairs along a long body indicate myriapods.
• Check body structure: elongated trunk with one pair of legs per segment fits myriapods like centipedes or millipedes.
• Rule out other groups: arachnids have eight legs, insects six, crustaceans typically aquatic with branched appendages.
• Confirm via arthropod classification: myriapods are terrestrial with numerous segments.

Why D is correct:

• Myriapods are defined as arthropods with a worm-like body and one pair of legs per trunk segment, matching elongated, multi-legged species.

Why the others are wrong:

• A: Arachnids have eight legs and no antennae or wings.
• B: Crustaceans are mostly aquatic with two pairs of antennae and biramous appendages.
• C: Insects have three body regions, six legs, and often wings or antennae.

Final answer: D