Please Help me to solve the question and explain also.

Hello Student,

We Know the charged particles will in such a way that to resist the appilied magnetic field.

Proton and electron will move such that it produce magnetic field in outward direction.
Since proton is positive particle, by right hand thumb rule, thumb outward and curl inACW.
Since electon is negative particle, by right hand thumb rule, thumb inward and curl in CW.

Since velocity and charge of two particle are equal the magnetic force on them will be equal.
Force = MV²/R
For same force, R is inversely proportional to mass M.
and mass of proton is greater than mass of electron.
Therefore, the radius of electron is more than proton.
Hence option Cis the correct answer.

Regards,
IHE