Two point charges are separated by 10.0 cm and have charges of 2.0 μC and -2 μC, respectively. What is the electric field at the point midway between the two charges? (k = 8.99 x 109 N.m2/C2)

A. 28.8 x 10 6
B. 14.4 x 106
C. 7.19 x 106
D. 3.59 x 106
E. zero

i am getting D...but i got that wrong i don't know how to solve it