$(A)$ decreasing the number of turns
$(B)$ increasing the magnetic field
$(C)$ decreasing the area of the coil
$(D)$ decreasing the torsional constant of the spring
Choose the most appropriate answer from the options given below.
[use $m _{p}=1.6 \times 10^{-27} kg , e =1.6 \times 10^{-19} C$ ]

Reason : Cyclotron frequency depends upon the velocity