Cho a = log 2 3, b = log 3 5, c = log 7 2. Hãy biểu diễn log 140 63 theo a, b, c

A. ${\log }_{140}63=\frac{2ac+1}{abc+c+1}$

B. ${\log }_{140}63=\frac{2ac+1}{abc+2c+1}$

C. ${\log }_{140}63=\frac{ac+1}{abc+c+1}$

D. ${\log }_{140}63=\frac{ac+1}{abc+2c+1}$