The direction of a charged particle’s velocity is slowly rotated from being parallel to a uniform magnetic field to being antiparallel (from 0∘ through 180∘). Which statement best describes how the magnitude of the magnetic force on the particle changes during this rotation?
a) It decreases from a maximum at 0∘ to zero at 90∘, then increases back to the same maximum at 180∘.
b) It increases from zero, reaches a maximum at 90∘, then decreases symmetrically to zero at 180∘.
c) It increases continuously from zero at 0∘ to a maximum at 180∘.
d) It remains constant for all angles.