An `(alpha)`-particle and a proton are both simultaneously projected in opposite direction into a region of constant magnetic field perpendicular to the direction of the field. After some time it is found that the velocity of the `(alpha)`-particle has changed in a direction by `45^(@)`. Then at this time, the angle between velocity vectors of `(alpha)`-particle and proton is

Options

A. `90^@`
B. `45^@`
C. `45^@+90^@`
D. `(45^@+90^@)/(2)`

Answer

C