A particle having a mass of `10^(-2) kg` carries a charge of `5 xx 10^(-8) C`. The particle is given an initial horizontal velocity of `10^(5) msec^(-1)` in the presence of electric field `vec(E)` and magnetic field `vec(B)`. To keep the particle moving in a horizontal direction, it is necessary that
A. `vec(B)` should be perpendicular to the direction of velocity and `vec(E)` should be along the direction of velocity
B. Both `vec(B)` and `vec(E)` should be along the direction of velocity
C. Both `vec(B)` and `vec(E)` are mutually perpendicular and perpendicular to the direction of velocity
D. `vec(B)` should be along the direction of velocity and `vec(E)` should be perpendicular to the direction of velocity