You Are Studying 112 Returning Combat Veterans with Deployment Related

You are studying 112 returning combat veterans with deployment related injuries. You are testing a cognitive impairment screen to detect traumatic brain injuries (TBI) . There are six veterans with confirmed TBI and five of them screen positive. There are 93 veterans who do not have TBI and screen negative. There are a total 18 veterans who screen positive. What is the specificity of the screen?

A) 89.4%
B) 87.7%
C) 83.3%
D) Unable to determine