Epidemiologists Decided to Investigate the Validity of New Diagnostic Tool

Epidemiologists decided to investigate the validity of new diagnostic tool for breast cancer.They used this new diagnostic tool for breast cancer in 150 women with biopsy-proven breast cancer in 300 age- and race-matched control women.The results of the new tool were positive in 136 cases and in 35 control women,all of whom showed no evidence of cancer at biopsy.Now,the epidemiologists want to use the new diagnostic tool for screening program in Cities A and B.Based on previous cross-sectional studies,the prevalence of breast cancer is 5% in City A and 1% in City B.What is the most reasonable conclusion to be drawn from these data?

A) Positive predictive value of new diagnostic tool for breast cancer in City A is higher than expected positive predictive value in City B.
B) Positive predictive values will be higher than sensitivity.
C) Positive predictive value is affected by the specificity of the test only.
D) Prevalence will not affect the positive predictive value.
E) Positive predictive value is a fixed characteristic of the test. Therefore the positive predictive value in City A will be same as positive predictive value in City B.