Are a collection of infected hair follicles that often occur on the back of the neck, the upper back, and lateral thighs that form a mass that evolves into an erythematous, painful, edematous mass, which drains through many openings.

Carbuncle

Explanation:

A carbuncle is a swollen, red and painful cluster of boils. These boils are connected under the surface of the skin. A boil in the case of a carbuncle can be described as an infection of a hair follicle. Each infected hair follicle has a small collection of pus.

A carbuncle is expected to develop in a hairy area of the body like the back of the neck, buttocks, groins, thighs and armpits. A carbuncle is edematous and drain with pus through opening.  

i think the answer is c

hope this