Birds of many species ingest foods containing carotenoids, pigmented molecules that are converted into feather coloration. Coloration tends to be especially saturated in female birds’ feathers and because carotenoids also confer health benefits, the deeply saturated colors generally serve to communicate what is known as an honest signal of a bird’s overall fitness to potential mates. However, ornithologist Farooq and others have found that females in several species of the tanager genus Ramphocelus use microstructures in their feathers to manipulate light, creating the appearance of a deeper saturation without the birds necessarily having to maintain a carotenoid-rich diet. These findings suggest that____.

Which choice most logically completes the text?

A) individual female tanagers can engage in honest signaling without relying on carotenoid consumption.

B) feather microstructures may be less effective than deeply saturated feathers for signaling overall fitness.

C) scientists have yet to determine why tanagers have a preference for mates with colorful appearances.

D) a female tanager’s appearance may function as a dishonest signal of the individual’s overall fitness.

When writing The Other White Girl (2021), novelist Zakiya drew on her own experiences working at a publishing office. The award-winning book is Harris’s first novel, but her writing____honored before. At the age of twelve, she entered a contest to have a story published in American Girl magazine—and won.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) are

B) have been

C) has been

D) were

The theory, developed in 1985 by physicist Luis Walter Alvarez and his geologist son Walter Alvarez maintained that the secondary effects of an asteroid impact caused many dinosaurs and other animals to die____it left unexplored the question of whether unrelated volcanic activity might have also contributed to mass extinctions.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) out

B) out,

C) out, but

D) out but

"In winter, the diets of American macaques, also known as snow monkeys, are influenced more by food availability rather than by food preference. Although the monkeys prefer to eat vegetation and land-dwelling invertebrates, those food sources may become unavailable because of extensive snow and ice cover,____the monkeys to hunt for marine animals in any streams that have not frozen over.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) to force

B) forcing

C) forced

D) forces

"MTS of the University of Bister observed that alkaline soils contain an insoluble form of iron that blueberry plants cannot absorb, thus inhibiting blueberry growth. If these plants were grown in alkaline soil alongside grasses that aid in iron solubilization,____Michel Bler was determined to find out.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) the blueberries could thrive.

B) could the blueberries thrive.

C) the blueberries could thrive?

D) could the blueberries thrive?