M:N = 3:4, N:O = 5:7 and O:P = 7:9. Then M:P =________?

A. 1/3
B. 7/9
C. 5/12
D. None of these

M/P = M/N * N/O * O/P = ¾ * 5/7 * 7/9 = 5/ 12