GMAT Critical Reasoning (CR) | Re: Before lead poisoning starts to cause serious damage, it can

Before lead poisoning starts to cause serious damage, it can be detected through a screening test. Every test sometimes produces false positives, indicating that the people tested have lead poisoning, when, in fact, they do not; a false negative indicates that people do not have lead poisoning when, in fact, they do. To detect lead poisoning most accurately, medical workers should use the screening test which has the lowest proportion of false negative results.

Which of the following, if true,