Which of the following is an example of onomatopoeia?

Onomatopoeia refers to words that phonetically imitate, resemble, or suggest the sound that they describe. In option A, words like "drip," "chirp," "splash," and "giggle" exemplify this concept because they mimic the sounds associated with the actions or objects they represent. For instance, "drip" resembles the sound of water falling drop by drop, "chirp" imitates the sound made by birds, "splash" conveys the sound of something striking the surface of liquid, and "giggle" mirrors the sound of laughter.

The other options consist of words that do not represent sounds. The second option lists verbs related to actions, which do not have a sound association. The third option contains adjectives describing emotions, while the last option presents color words. None of these options provide examples of sounds or sound-like expressions, which is the essence of onomatopoeia.