Charged particles enter, perpendicularly, uniform electric and uniform magnetic fields. Which of the following correctly describes the shape of the path taken by the charged particle in the field?
a. Uniform electric field: Circular; Uniform magnetic field: Circular
b. Uniform electric field: Circular; Uniform magnetic field: Parabolic
c. Uniform electric field: Parabolic; Uniform magnetic field: Circular
d. Uniform electric field: Parabolic; Uniform magnetic field: Parabolic