Final answer:
The expression about the leopard's spots means that external conditions do not change a person's true nature, similar to how rain doesn't change leopard's spots. Therefore, the correct answer to the student's question is b) Appearances can be deceiving, and one's true nature remains unchanged.
Step-by-step explanation:
The expression "the rain wets the leopard but it doesn't wash out his spots" is an idiomatic phrase that holds a figurative meaning. To understand this saying, one must think about the nature of a leopard's spots, which are inherent characteristics that won't change regardless of the weather or conditions they're subjected to. In the same way, the phrase implies that a person's true nature or inherent qualities do not change, even when external circumstances, like the rain, seem to make an impact. Therefore, the correct answer to the student's question is b) Appearances can be deceiving, and one's true nature remains unchanged. Unlike the literal sentences that describe rain on the pavement, this expression uses the imagery of a leopard and its spots symbolically, to convey that while the rain may wet the leopard, it does not alter its distinctive spots. In essence, this proverbial phrase suggests that superficial changes do not affect the fundamental nature of something or someone.