One person is selected at random from a group of 25 people. The probability that the selected person will be male is 0.64. The probability that the selected person will be female is 0.36. If a male is selecte the probability that he was born before 1970 is 0.375. Which of the following represents the ratio of males born before 1970 to the total number of females?

a. 1:1
b. 2:3
c. 3:4
d. 3:2