What is keratin's role in nails?

Keratin plays a crucial role in the composition and functionality of nails, as it is the primary protein that forms their structure. Being a fibrous structural protein, keratin provides nails with the necessary strength and resilience required to withstand everyday activities and potential trauma. This is essential for maintaining the integrity of the nail as it protects the distal phalanx, the fingertip, and surrounding soft tissues from environmental damage.

While some options touch on aspects related to nails, they do not capture the fundamental role of keratin as effectively as the correct choice. For instance, while options that mention softening or enhancing color might address certain superficial aspects, they do not reflect the structural significance that keratin contributes to nail health and durability. Similarly, acting as a protective layer, while relevant, does not specifically highlight keratin's contribution to structural integrity and strength in the way that option B does.