Which of the following is an example of personification?

Personification is a literary device where human traits or behaviors are attributed to non-human entities or objects. In this case, the option describing the breeze gently helping the leaves dance exemplifies personification because it gives the breeze a human ability: to help. The imagery evokes a sense of a gentle, caring force guiding the leaves, which enhances the emotional and visual impact of the description.

The other options describe comparisons or similes that do not bestow human characteristics on the non-human elements. For instance, comparing the clouds to cotton candy, the car to a cheetah, and the stars to diamonds illustrates similarities or likenesses rather than inferring human qualities. Thus, option C distinctly stands out as the correct example of personification by embodying the breeze with human-like actions.