Read this section of Uriel’s report about flightless birds.

Flightless birds are birds that cannot fly. Scientists do not agree on whether the ancestors of these birds could fly. However, most experts understand that flightless birds are missing body parts that allow other birds to fly.

What should Uriel do to help his readers understand the text, and why?

A.
Set the terms flightless and
ancestors in boldface text so readers understand that these are key words that they should look up.
B.
Create a timeline showing when the ancestors of flightless birds became extinct so readers will understand when birds became flightless.
C.
Add a map showing the location of flightless birds in the world so readers understand the connection between flightlessness and country of origin.
D.
Include labeled illustrations of a flightless bird and a flying bird so readers understand which parts the flightless bird is missing that would allow it to fly.