What gets wetter as it dries?

The answer is a towel, as it effectively captures the essence of the riddle. When you use a towel to dry something, such as your body or hands, the towel absorbs the moisture, causing it to become wetter while it performs its drying function. This playful wordplay illustrates a counterintuitive situation where an object becomes more saturated while fulfilling its purpose, creating a sense of surprise that challenges direct logical thinking.

In contrast, the other options do not fit the riddle in the same way. A sponge, while it absorbs water, does not typically dry anything in a traditional sense as a towel does. A piece of cloth could also absorb moisture, but it's less commonly associated with drying in the same specific manner as a towel. A raindrop, on the other hand, does not dry anything; instead, it contributes to wetness. The clever nature of the riddle highlights the unique role of the towel in this context.