A Particle (Q = -4 $\mu$ C,m = 50 Mg)moves in a Uniform Magnetic Field with a Velocity

A particle (q = -4.0 $\mu$ C,m = 5.0 mg) moves in a uniform magnetic field with a velocity having a magnitude of 2.0 km/s and a direction that is 50 $\degree$ away from that of the magnetic field.The particle is observed to have an acceleration with a magnitude of 5.8 m/s².What is the magnitude of the magnetic field?

A) 5.3 mT
B) 4.9 mT
C) 5.1 mT
D) 4.7 mT
E) 3.6 mT