Some species of dolphins use echolocation to find prey: they emit ticking sounds and then receive echoes from distant objects in the water. Marine biologists speculate that these ticks may have another effect: Dolphins use unusually high-frequency ticks The sound overloads the prey's senses, thereby stunning the prey at close range. Which of the following, if true, would most challenge the above speculation? ['Dolphins use echolocation to find not only long-range prey, but also mid-range prey.', 'As a signal to find prey, the ticking sound of the dolphin cannot be sensed by the senses of its prey, only the dolphin can perceive it, so as to locate.', 'The high-frequency signal from the dolphin is short-lived, even if it can stun the prey.', 'The sound waves emitted by a bat not only make it find its prey, but this sound wave can form a special stimulus to the prey, thereby helping the bat to capture them.']