Which feature helps distinguish insects from other arthropods?

• A. A hard exoskeleton
• B. The presence of antennae
• C. Three wings
• D. Two body segments

Answer: (B)

Insects are identified in part by sensory structures on the head, specifically a pair of antennae. These antennae are characteristic of insects and serve as key tools for sensing the environment, which helps distinguish them from other arthropods such as arachnids that lack antennae. The other options don’t provide as reliable a distinction: a hard exoskeleton is common to all arthropods, not unique to insects; three wings aren’t universal since many insects have two wings or no wings at all; and two body segments don’t match the typical insect body plan of head, thorax, and abdomen. So, the presence of antennae best helps tell insects apart from other arthropods.