Which of the Following Statements Describes a Vestigial Trait

Which of the following statements describes a vestigial trait?

A) Whales and dolphins must breathe air even though they spend their entire lives in the water.
B) Penguins are flightless birds with wings that are specialized for swimming.
C) Humans still have eyebrows, even though we have much less body hair than chimps.
D) Kiwis are flightless birds with reduced, nonfunctional wings.
E) Snakes have hinged jaws to help them swallow large meals.