Which of the following is an essential step before applying nail enhancements?

Cleaning the nail surface is an essential step before applying nail enhancements because it ensures that any oils, dirt, or residues that may interfere with the adhesion of the enhancement product are removed. A clean surface allows for better bonding between the natural nail and the enhancement, which leads to a more durable and long-lasting result. By properly cleaning the nails, you also help to prevent lifting and potential infections that could arise from trapped debris under the enhancement.

Other steps, like polishing and buffing, may come into play later in the process but do not specifically address the fundamental need to prepare the nail surface for enhancement application. Applying a top coat before the enhancement is also not appropriate, as it would obstruct the adhesion process. Thus, cleaning the nail surface is a critical first step before any enhancements can be successfully applied.