A river is flowing with a speed of 1 km/hr. A swimmer wants to go to point C starting from A. He swims with a speed of 5km/hr. at an angle `theta`. W.r.t. the river flow. If AB=BC=400m at what angle with river tank shou ld swimmer swim?
A. `37^(@)`
B. `53^(@)`
C. `0^(@)`
D. `90^(@)`
