The mano energetic beams of electrons moving along `+y` direction enter a region of uniform electric and magnetic fields. If the beam goes straight through these simultaneously then field `B` and `E` are directed respectively along.
A. `-y` axis and `-z` axis
B. `+z` axis and `-x` axis
C. `+x` axis and `-x` axis
D. `-x` axis and ``-y` axis
