A drug test for athletes has a 6% false positive rate and a 10% false negative rate. Of the athletes tested, 4% have actually been using the prohibited drug. Now, in keeping with the notation that we are familiar with, think of A = event that the drug test is positive, and B = event that the drug is actually taken. If a sample of athletes test positive, what is the probability that a randomly chosen athlete from this sample has actually been using the prohibited drug?

a. 0.489
b. 0.168
c. 0.385
d. 0.761