A Proton,starting from Rest,accelerates Through a Potential Difference of 1

Multiple Choice

A proton,starting from rest,accelerates through a potential difference of 1.0 kV and then moves into a magnetic field of 0.040 T at a right angle to the field.What is the radius of the proton's resulting orbit? (e = 1.60 × 10^-19 C,m_proton = 1.67 × 10^-27 kg)

A) 0.080 m
B) 0.11 m
C) 0.14 m
D) 0.17 m