What is the strength of the electric field midway between an electron and a proton separated by 0.2 nm?

A) 0.9 × 10ⁱ² N/C
B) 1.8 × 10ⁱ² N/C
C) 3.6 × 10ⁱ² N/C
D) 7.2 × 10ⁱ² N/C