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The passage given below is followed by four alternate summaries. Choose the option that best captures the essence of the passage.

North American walnut sphinx moth caterpillars (Amorpha juglandis) look like easy meals for birds, but they have a trick up their sleeves-they produce whistles that sound like bird alarm calls, scaring potential predators away. At first, scientists suspected birds were simply startled by the loud noise. But a new study suggests a more sophisticated mechanism: the caterpillar's whistle appears to mimic a bird alarm call, sending avian predators scrambling for cover. When pecked by a bird, the caterpillars whistle by compressing their bodies like an accordion and forcing air out through specialized holes in their sides. The whistles are impressively loud they have been measured at over $80 \mathrm{~dB} from \5 \mathrm{~cm}$ away from the caterpillar considering they are made by a two-inch long insect.

Solution

βœ… Correct Option: 3

The key to solving this lies in identifying the main discovery -> what makes these caterpillars special is not just that they whistle, but how and why they whistle.

From passage: "the caterpillar's whistle appears to mimic a bird alarm call, sending avian predators scrambling for cover"

The passage moves from simple explanation (loud noise scares birds) -> sophisticated mechanism (mimicking bird alarm calls). This is acoustic deception - using sound to trick predators by copying bird warning sounds.


Let's eliminate the wrong options by spotting what they miss or add incorrectly:

πŸ”΄ Option 1 -> factual-error -> says "specialized vocal tract" but passage clearly states they compress bodies and use "holes in their sides" (not vocal cords like birds have)

πŸ”΄ Option 2 -> scope-error -> only focuses on loudness but completely misses the main point about mimicking alarm calls. This is like describing a magic trick by only talking about how bright the lights are!

🟒 Option 3 -> captures essence perfectly -> mentions both "acoustic deception" AND "mimic bird alarm calls" - hits the core discovery

πŸ”΄ Option 4 -> adds-irrelevant-info -> mentions "camouflage" which isn't in passage at all. Also drops "acoustic" which is crucial to understanding the type of deception (sound-based, not visual)

The confusion students face: Options 3 vs 4 both mention deception and mimicking. But Option 4 adds "camouflage" (visual hiding) when the passage only discusses sound-based deception.

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