The correct answer is A. Alopecia areata.
Alopecia areata presents with discrete, round or oval patches of non-scarring hair loss. Initial sparing of non-pigmented hair may occur leading patients to report rapid whitening of the hair. Similarly, initial regrowth of hair may include white or grey hairs.
Incorrect: Trichotillomania is an impulse disorder characterized by repetitive hair pulling. As a result, varying lengths of hair can be seen within areas of alopecia. The mainstay of treatment is behavioral modification.
Androgenetic alopecia is an androgen-dependent form of nonscarring alopecia. It affects men more commonly than women and frequency increases with age. The characteristic pattern in men includes frontal parietal recession and thinning of the vertex hair. In women, central thinning is most commonly seen.
Traction alopecia is the result of chronic mechanical trauma to the frontal and bitemporal scalp. Though initially nonscarring, with repetitive traction, hair loss can become permanent.
Temporal triangular alopecia is a form of congenital alopecia. Presenting at birth or in early childhood, there is unilateral or bilateral nonscarring alopecia of the temporal area. The hair loss is permanent.