As part of the study described in Problem 6, investigators wanted to assess the accuracy of self-reported smoking status. Participants are asked whether they currently smoke or not. In addition, laboratory tests are performed on hair samples to determine presence or absence of nicotine. The laboratory assessment is considered the gold standard, or truth about nicotine consumption. The data are as follows:

Nicotine Absent (NB)

Nicotine Present (NP)

NB NP

Self-reported non smoker| 100 | 19

Self-reported smoker | 18 | 52

What is the specificity of self-reported smoking status?

A)1

B)0.90

C)0.85

D)0.56

Please provide answer and explanation