A proton and an electron in a hydrogen atom are separated by a distance of 5.3 x 10-11 m. The magnitude and direction of electric field set up by the proton at the position of the electron is:
a. 5.1 x1011 N/C away from the proton
b. 5.1 x1011 N/C toward the proton
c. 5.1 x1010 N/C toward the proton
d. 5.1 x1010 N/C away from the proton