In a survey of 248 people, 156 are married, 70 are self-employed, and 25% of those who are married are self-employed. If a person is to be randomly selected from those surveyed, what is the probability that the person selected will be self-employed but not married?
A. 1/8
B. 4/31
C. 117/248
D. 1/4
E. 31/117