What type of fungal infection is often reflected by thickened nails?

Onychomycosis is the correct response because it specifically refers to a fungal infection that affects the nails, leading to symptoms such as thickening, discoloration, and possible fragility of the nails. This condition occurs when fungi invade the nail matrix or the nail bed, resulting in changes to the texture and shape of the nail, which often appears thickened and may also become discolored.

Tinea pedis, commonly known as athlete's foot, primarily affects the skin on the feet and does not directly cause thickened nails, even though it is a fungal infection. Paronychia refers to an infection of the skin around the nails, which may lead to swelling and redness but not necessarily thickening of the nails themselves. Onychia is an inflammation of the nail matrix, which can result in nail damage but is not specifically characterized by thickened nails. Therefore, the clear association of thickened nails with onychomycosis makes it the correct answer.