Which statement about the impact of product buildup on hair is correct?

Product buildup refers to the accumulation of various hair products, such as conditioners, gels, and sprays, on the hair strands and scalp over time. This buildup can restrict moisture and prevent the hair from getting the nutrients and care it needs. When hair is affected by product buildup, it often appears dull and lifeless. The residue from products can weigh the hair down, making it look lackluster and devoid of its natural shine. In addition to aesthetic issues, the buildup can also affect the scalp, potentially leading to irritation or affecting hair growth. Proper cleansing and clarifying treatments are essential to remove this buildup and restore the hair's vibrancy.

The other statements do not accurately reflect the effects of product buildup. It neither strengthens the hair nor protects it from damage—in fact, it typically has the opposite effect. Additionally, rather than making hair easier to style, buildup often complicates styling efforts, resulting in a stiff or weighed-down appearance.