A motor boat is to reach to a point `30^(@)` upstream on other side of a river flowing with velocity `5 m//s`.Velocity of motor boat with respect to water is `5sqrt3m//sec`.The driver should steer the boat at an angle of
A. `30^(@)` up w.r.t. the line of destination from the starting point
B. `60^(@)` up w.r.t. normal to the bank
C. `120^(@)` w.r.t. stream direction
D. None of these