A Negatively-Charged Particle Moves Across a Constant Uniform Magnetic Field

Multiple Choice

A negatively-charged particle moves across a constant uniform magnetic field that is perpendicular to the velocity of the particle. The magnetic force on this particle

A) causes the particle to speed up.
B) is in the same direction as the particle's velocity.
C) causes the particle to accelerate.
D) is opposite the direction of the particle's velocity.
E) causes the particle to slow down.