A Screening Test for a Newly Discovered Disease Is Being

A screening test for a newly discovered disease is being evaluated. In order to determine the effectiveness of the new test, it was administered to 900 workers. 150 of the individuals diagnosed with the disease tested positive. A negative test finding occurred in 60 people who had the disease. A total of 50 persons without the disease tested positive for it. Assume the prior probability is not known.
-What is the prevalence of disease cases in the population?

A) 77%
B) 75%
C) 9%
D) 23%
E) None of these is correct.