What is the correct answer?

4

A. 39800

B. 38700

C. 36700

D. 37800

72 = 2^{3} x 3^{2}, 108 = 3^{3} x 2^{2}, 2100 = 2^{2} x 5^{2} x 3 x 7.

L.C.M. = 2^{3} x 3^{3} x 5^{2} x 7 = 37800.