Velvety patches on the back of the neck

NEET PG Dermatology
#1

A 55-year-old obese patient presents with dirty, velvety patches on the back of the neck:

A) Keloids
B) Erythema nodosum
C) Acanthosis nigricans
D) Erythema multiforme
E) Acne vulgaris

Ans: C) Acanthosis nigricans