The correct answer is A. Lichen planopilaris.

In a middle-aged white woman with pruritic hair loss with an examination showing significant perifollicular erythema and scarring, consider the diagnosis of lichen planopilaris of the options provided.

Alopecia areata and androgenetic alopecia traditionally are nonscarring alopecias, inconsistent with this image of scarring alopecia. Central centrifugal cicatricial alopecia usually appears in Black women on the vertex of the scalp and lacks the scale and erythematous follicular spines seen here. Discoid lupus erythematosus is not likely to surround follicles, as seen here. Folliculitis decalvans is a cicatricial alopecia associated with pustules, which is not consistent with the image shown.

References: Ross EK, Tan E, Shapiro J. Update on primary cicatricial alopecias [published correction appears in J Am Acad Dermatol. 2005 Sep;53(3):496]. J Am Acad Dermatol. 2005;53(1):1-40.