An electron, a proton, a deuteron and an alpha particle, each having the same speed are in a region of constant magnetic field perpendicular to the direction of the velocities of the particles. The radius of the circular orbits of these particles are respectively `R_(e), R_(p), R_(d)` and `R_(alpha)` It follows that

Options

A. `R_(e)=R_(p)`
B. `R_(p)=R_(d)`
C. `R_(d)=R_(alpha)`
D. `R_(p)=R_(alpha)`

Answer

C