Final answer:
The magnetic force on the electron is -3.84 x 10^-14 N in the negative z direction.
Step-by-step explanation:
The magnetic force on an electron moving in a magnetic field can be determined using the equation:
F = q * v * B * sin(theta)
Where:
F is the magnetic force
q is the charge of the electron
v is the velocity of the electron
B is the magnetic field
theta is the angle between the velocity vector and the magnetic field vector.
In this case, the electron has a negative charge
a velocity of 3 x 10^5 m/s in the positive x direction, and the magnetic field is 0.8 T in the positive z direction.
The angle between the velocity and the magnetic field is 90 degrees, so sin(theta) = 1.
Plugging in the values:

Therefore, the magnetic force on the electron is
in the negative z direction. The correct answer is c.