At a certain school, the ratio of the number of second graders to the number of fourth-graders is 8 to 5, and the ratio of the number of first graders to the number of second graders is 3 to 4. If the ratio of the number of third-graders to the number of fourth-graders is 3 to 2, what is the ratio of the number of first graders to the number of third-graders?
A. 16 to 15
B. 9 to 5
C. 5 to 16
D. 5 to 4
E. 4 to 5
Answer: E
Source: Official Guide