Answer: C
Z71.7 is the most appropriate code as it codes specifically for an encounter for HIV counseling.
Option A is incorrect because the R75 code is used to specify a diagnosis of inconclusive laboratory evidence of human immunodeficiency virus [HIV]. Here, the female clients went for counselling.
Option B is incorrect because Z21 code is used to specify a diagnosis of asymptomatic human immunodeficiency virus [HIV] infection status which is not mentioned in this case.
Option D is incorrect because B20 is used to specify symptomatic AIDS infection which is not appropriate here.
