A particle (m = 3.0 µg, q = 5.0 µC) moves in a uniform magnetic field given by (60j)mT. At t = 0 the velocity of the particle is equal to (30j - 40k) m/s. The subsequent path of the particle is:
a) circular with a 50cm radius
b) helicila with 6.3 cm pitch
c) circular with a period of 31 ms
d) helicial with 40cm radius
e) none of the above