How does excessive exposure to water affect nails?

Excessive exposure to water can lead to breakage and splitting of nails because it disrupts the natural balance of moisture within the nail structure. When nails are exposed to water for prolonged periods, they tend to absorb the water, causing them to swell. This swelling weakens the keratin structure of the nails, making them more prone to damage. Once the nails dry out after being wet, they can become brittle and more likely to crack or split.

The other chosen options suggest positive effects of water on nails, such as enhancing strength or increasing hardness, which do not accurately reflect the consequences of excessive water exposure. While some moisture is necessary for nail health, too much can have detrimental effects, reinforcing the idea that a balance is critical.