What can be said about insects?

• A. They are vertebrates.
• B. They have three pairs of jointed legs.
• C. They have no legs.
• D. They have four pairs of legs.

Answer: (B)

Insects are invertebrate arthropods with a body divided into head, thorax, and abdomen, and they have an exoskeleton. A defining feature is that they have three pairs of legs attached to the thorax, giving them six legs in total. This is why the statement about having three pairs of jointed legs is true and best describes insects. The other ideas don’t fit: insects are not vertebrates because they lack a backbone, they do have legs (so “no legs” is false), and they do not have four pairs of legs (that trait belongs to arachnids, which have eight legs). Wings may be present or absent in different species, but the number of legs remains six.