Which of the following tools is essential for nail art?

The dotting tool is essential for nail art because it is specifically designed to create intricate designs and patterns on the surface of the nails. Its rounded ends allow for the precise deposition of polish, acrylics, or other nail products, which is vital for techniques such as dotting, creating flowers, or adding delicate details and highlights to nail art.

While tools like a cuticle pusher, nail clipper, and nail file serve important functions in nail care, they are primarily focused on shaping, maintaining, or preparing the nails rather than creating artistic designs. For instance, a cuticle pusher is used for pushing back cuticles, a nail clipper is meant for trimming nails, and a nail file smooths out edges and shapes the nail contour. None of these tools facilitate the actual artistic application needed for decorative nail work in the same way that a dotting tool does.