In a Mass Spectrometer, Chlorine Ions of Mass 35u and Charge

In a mass spectrometer, chlorine ions of mass 35u and charge +5e are emitted from a source and accelerated through a potential difference of 250 kV. They then enter a region with a magnetic field, which is perpendicular to their original direction of motion. The chlorine ions exit the spectrometer after being bent along a path with a radius of curvature 3.5 m. What is the value of the magnetic field u = 1.66 × 10^-27 kg, e = 1.6 × 10^-19 C) ?

A) 3.9 × 10^-2 T
B) 2.5 × 10^-2 T
C) 3.1 × 10^-2 T
D) 5.4 × 10^-2 T
E) None of the above.