Water is flowing through a capillary tube at the rate of `20xx10^(-6)m^(3)//s`. Another tube of same radius and double the length is connected in series to the first tube. Now the rate of flow of water in `m^(3)s^(-1)` is
A. `10xx10^(-6)`
B. `3.33xx10^(-6)`
C. `6.67xx10^(-6)`
D. `20xx10^(-6)`