The poison dart frog secretes potent chemicals through its skin to deter predators. Paradoxically, in some ecosystems, the very toxins the frog produces to ensure its safety actually ______ the likelihood of detection, as certain predators have evolved to track the scent of these chemicals.
7
readingWhich choice completes the text so that it conforms to the conventions of Standard English?
A
increases
B
increase
C
is increasing
D
has increased
Correct Answer: B
Choice B is the best answer. The subject is "the very toxins" (plural). The verb must agree with the plural subject. "Increase" is the plural, simple present form.