318. Data on a certain pregnancy test show that a pregnant woman will test negative or not pregnant 10% of the time, while a non-pregnant woman will test positive 20% of the time. Thirty percent of the women who take the test are pregnant. Calculate the probability that a woman is pregnant given that her test outcome is positive. (A) 0.18 (B) 0.30 (C) 0.66 (D) 0.82 (E) 0.90