What does excessive buffing of nails cause?

Excessive buffing of nails results in over-smoothness, which can make them more susceptible to breakage. When nails are buffed too much, it removes not only the superficial layers of the nail but can also lead to a thinning of the nail plate. A healthier nail structure relies on having an adequate thickness, which provides strength and durability. Overly buffed nails lose their natural resilience and may develop weaknesses, increasing the likelihood of cracks and splits.

In contrast, while buffing can enhance the nail's shine and appearance, excessive buffing detracts from the natural integrity of the nails, making option B the most accurate answer. It addresses the negative impact of improper buffing techniques rather than the superficial improvements that might occur with moderate buffing.