$A$ proton of mass $1.67 \times 10^{-27} \, kg$ and charge $1.6 \times 10^{-19} \, C$ is projected with a speed of $2 \times 10^6 \, m/s$ at an angle of $60^{\circ}$ to the $X$-axis. If a uniform magnetic field of $0.104 \, T$ is applied along the $Y$-axis,the path of the proton is:

• A
  $A$ circle of radius $\cong 0.1 \, m$ and time period $2\pi \times 10^{-7} \, s$.
• B
  $A$ circle of radius $\cong 0.2 \, m$ and time period $7\pi \times 10^{-7} \, s$.
• C
  $A$ helix of radius $\cong 0.1 \, m$ and time period $2\pi \times 10^{-7} \, s$.
• D
  $A$ helix of radius $\cong 0.2 \, m$ and time period $4\pi \times 10^{-7} \, s$.