Let `r_(1)(t)=3t hat(i)+4t^(2)hat(j)`
and `r_(2)(t)=4t^(2) hat(i)+3that(j)`
represent the positions of particles 1 and 2, respectiely, as function of time t, `r_(1)(t)` and `r_(2)(t)` are in metre and t in second. The relative speed of the two particle at the instant t = 1s, will be
A. 1m/s
B. `3sqrt(2)m//s`
C. `5sqrt(2)m//s`
D. `7sqrt(2) m//s`