Given the Persistent Questions, Controversies, and Inadequacies of the Polygraph

Given the persistent questions, controversies, and inadequacies of the polygraph, what should an employer do if using polygraph as a screening tool?

A) Give the candidate a chance to challenge any negative results.
B) Give each candidate a polygraph examination three times and take the average of the results.
C) Use the results of the polygraph only if the candidate has other obvious problems in his background check.
D) Present the findings to a candidate's former employers for feedback on accuracy.