Which choice best reflects the overall sequence of events in the passage?

A) An experiment is proposed but proves unworkable; a less ambitious experiment is attempted, and it yields data that give rise to a new set of questions.

B) A new discovery leads to reconsideration of a theory; a classic study is adapted, and the results are summarized.

C) An anomaly is observed and simulated experimentally; the results are compared with previous findings, and a novel hypothesis is proposed.

D) An unexpected finding arises during the early phase of a study; the study is modified in response to this finding, and the results are interpreted and evaluated.

As used in line 7, “challenged” most nearly means

A) dared.

B) required.

C) disputed with.

D) competed with.

Which statement best captures Ken Dial’s central assumption in setting up his research?

A) The tendency of certain young birds to jump erratically is a somewhat recent evolved behavior.

B) The acquisition of flight in young birds sheds light on the acquisition of flight in their evolutionary ancestors.

C) Young birds in a controlled research setting are less likely than birds in the wild to require perches when at rest.

D) Ground-dwelling and tree-climbing predecessors to birds evolved in parallel.

Which choice provides the best evidence for the answer to the previous question?

A) Lines 1-4 (“At field…​ parents”)

B) Lines 23-24 (“At first . . . the ground”)

C) Lines 16-19 (“When…​ measured”)

D) Lines 6-11 (“So when…​ fly”)

In the second paragraph (lines 12-32), the incident involving the local rancher mainly serves to

A) reveal Ken Dial’s motivation for undertaking his project.

B) underscore certain differences between laboratory and field research.

C) show how an unanticipated piece of information influenced Ken Dial’s research.

D) introduce a key contributor to the tree-down theory.