A Proton,which Moves Perpendicular to a Magnetic Field of 0

Multiple Choice

A proton,which moves perpendicular to a magnetic field of 0.8 T in a circular path of radius 0.062 m,has what speed? (q_p = 1.6 × 10−¹⁹ C and m_p = 1.67 × 10−²⁷ kg)

A) 2.9E+5 m/s
B) 1.3E+7 m/s
C) 7.4E+6 m/s
D) 4.8E+6 m/s
E) ​1.9E+6 m/s