Passage Summary: These monkeys have different warning shouts depending on whether a predator is attacking from the ground or the sky.

Reasoning: Vervet monkeys utilize distinct alarm calls to signal the presence of predators based specifically on whether the predator is terrestrial or aerial.

Analysis: This stimulus presents a specific behavior that requires an explanation: why distinguish between land and air predators? In 'Paradox' or 'Explanation' questions, we need a piece of information that makes this distinction functional or necessary. If the monkeys reacted the same way to every predator, they wouldn't need different calls. Therefore, look for an answer that suggests the monkeys must take different defensive actions depending on where the threat comes from—such as climbing a tree to escape a leopard but hiding in bushes to escape an eagle.