If `G_(1),G_(2)` are the geometric means fo two series of observations and G is the GM of the ratios of the corresponding observations then G is equal to
A. `(G_(1))/(G_(2))`
B. `log G_(1) -log G_(2)`
C. `(log G_(1))/(log G_(2))`
D. `log(G_(1) *G_(2))`
