Which of the following methods is appropriate for prepping the nail before acrylic application?

Buffing the nail surface is the appropriate method for prepping the nail before acrylic application. This step is essential as it helps to remove any natural oils, dirt, and dead skin from the nail, creating a smoother surface that promotes better adhesion of the acrylic product. Additionally, buffing creates microscopic scratches on the nail plate, which increases the surface area that the acrylic can bond to, leading to a more durable and longer-lasting application.

Soaking the nails in warm water, while it may help in softening the cuticles, does not prepare the nail surface adequately for acrylics. Applying cuticle oil is typically done after the acrylic application to nourish the cuticles and surrounding skin rather than being a preparatory step. Painting a base coat is related to natural nail polish rather than acrylic preparation, as it serves a different purpose related to enhancing the longevity and appearance of nail polish rather than addressing the adhesion needs for acrylics.