How is a normal healthy nail typically described?

A normal healthy nail is characterized as firm, slightly pink, and smooth. This description reflects the typical appearance and texture of healthy nails. The firmness indicates that the nails are strong and not overly soft or weak, while the slight pink color is a sign of good circulation and health beneath the nail bed. Smoothness is essential as it indicates that the nail's surface is not damaged or compromised by issues such as ridges, bumps, or discoloration. These features together signify overall nail health, making option B the correct choice.

The other options describe qualities that are generally associated with unhealthy or problematic nails, such as brittleness, roughness, or flakiness, which do not align with the characteristics of a normal healthy nail.