Question

dolphins frequently attack fishing nets for food, causing fishers to lose income and putting themselves at the risk of injury from the nets. to address this issue, maña garagouni and her team of researchers coated a set of nets in capsaicin, the chemical that makes chili peppers spicy, in the hope that the nets would then be too unpleasant - tasting for the dolphins to get past. however, the capsaicin had no effect on the dolphins willingness and ability to attack. these results
which choice most logically completes the text?
a prove that dolphins are not physically sensitive to capsaicin.
b suggest that dolphins actually enjoy the flavor of capsaicin.
c indicate that capsaicin is an ineffective deterrent, but not why.
d suggest that the researchers coated the nets improperly.

Explanation:

The text states that capsaicin (the spicy chemical) had no effect on dolphins' willingness/ability to attack the nets. Option A says this proves dolphins aren't physically sensitive to capsaicin, which matches the result (no effect implies insensitivity). Option B is wrong as there's no info dolphins enjoy it. Option C says "indicate capsaicin is an ineffective deterrent" but the study's aim was to see if it deters; since it had no effect, it's ineffective, but does the result "indicate" that? Wait, the result is "no effect on willingness/ability to attack", so capsaicin didn't deter. But option A: the key is "prove that dolphins are not physically sensitive to capsaicin"—if capsaicin (which is spicy) had no effect, that suggests they aren't sensitive to its physical (spicy) effect. Option A is more direct: the lack of effect on their attack (due to capsaicin's spiciness) proves they aren't sensitive to capsaicin's physical (spicy) property. Option C: "ineffective deterrent"—but the study was to test if it's a deterrent. The result is no effect, so capsaicin is an ineffective deterrent. But which is better? Wait, the sentence is "These results ______". The results are "capsaicin had no effect on the dolphins’ willingness and ability to attack". So:

• A: Prove dolphins not sensitive to capsaicin. If capsaicin (spicy) had no effect, that supports they aren't sensitive to its physical (spicy) effect. Correct, because capsaicin's effect is physical (spicy), so no effect on attack (their behavior related to the net) implies they don't feel the spiciness (not sensitive).

• B: Wrong, no info they enjoy.

• C: "indicate that capsaicin is an ineffective deterrent, but not why"—the result shows it's ineffective (since it didn't deter), but does it "indicate" that? The result is no effect on attack, so capsaicin didn't deter, so it's ineffective. But the "but not why" part: the text doesn't give a why, but does the result indicate it's ineffective? Yes, but option A is more about the cause (sensitivity). Wait, the study's hypothesis was that capsaicin would make the nets unpleasant, so dolphins would avoid. The result is no effect, so either capsaicin didn't make the nets unpleasant (so dolphins aren't sensitive to capsaicin) or they didn't care. But the key is the effect on their willingness/ability to attack. If capsaicin is supposed to be a physical deterrent (spicy), then no effect suggests they aren't sensitive to capsaicin's physical effect. So A is better: the results prove (or support) that dolphins aren't sensitive to capsaicin (since the spicy chemical had no effect on their attack behavior).

• D: Wrong, no info about improper coating.

So A is correct.

Answer:

A. prove that dolphins are not physically sensitive to capsaicin.