Question

whales are thought to have evolved from land animals similar to large otters. as evidence of this, whales have useless leg bones (structures c) that float inside their bodies. these leg bones are ______ structures. a vestigial b homologous c analogous d evolutionary

Explanation:

Vestigial structures are remnants of organs or structures that had a function in an early ancestor. Whale leg bones are vestigial because they are remnants from their land - dwelling ancestors and no longer serve the original function of legs (since whales are aquatic). Homologous structures are similar due to common ancestry but may have different functions, analogous structures are similar in function but not ancestry, and "evolutionary" is not a type of structure in this context.

Answer:

A. vestigial