An athlete suspected of using steroids is given two tests that operate independently of each other. Test A has probability 0.9 of being positive if steroids have been used. Test B has probability 0.8 of being positive if steroids have been used. What is the probability that neither test is positive if steroids have been used?

(a) 0.72

(c) 0.02

(e) 0.08

(b) 0.38

(d) 0.28