A uniform 1 T magnetic field is directed vertically downward in a region of space. A proton traveling 10^5 m/s in a horizontal plane and aimed northward enters this region. The initial acceleration of the proton is:
a. 1.6 x 10^-14 m/s^2 westward
b. b. 9.6 x 10^12 m/s^2 eastward
c. 1.6 x 10^-14 m/s^2 eastward
d. 9.6 x 10^12 m/s^2 westward