In some class, we have 100 students,of which 40 percent are female. Among the female students, 30 students are business majors, all other female are computer majors. For male students, half are business major and half are computer major. If I random select a female student, what is the probability she is computer major? (A) 0.3 (B) 0.25 (C) 0.4 (D) 0.5 (E) none of the above