A small block of mass m, having charge q, is placed on a frictionless fixed inclined plane making an angle $\theta$ with the horizontal. There exists a uniform magnetic field B parallel to the inclined plane but perpendicular to the length of spring. If m is slightly pulled on the incline in downward direction and released, then the time period of oscillations of the block will be (assume that the block does not leave contact with the plane)

• A

  $2\pi \sqrt{\frac{m}{K}}$

• B

  $2\pi \sqrt{\frac{2m}{K}}$

• C

  $2\pi \sqrt{\frac{qB}{K}}$

• D

  $2\pi \sqrt{\frac{qB}{2K}}$