A screening test is used in the same way in two similar populations;but the proportion of false positive results among those who test positive in population A is lower than those who test positive in population B.What is the likely explanation?

• A. The specificity of the test is lower in population A
• B. The prevalence of the disease is lower in population A
• C. The prevalence of the disease is higher in population A
• D. The specificity of the test is higher in population A