[单选题]
An electron and a proton are separated by a distance of 1.0 m /(bt8g pzfkt8 r4tq xfv-o(9v. What (l c.kl2.ses1pge 2izhappens to the mazceg..2ks (pil12se lgnitude of the force on the first electron if a second electron is placed next to the proton?
A. It doubles.
B. It does not change.
C. It is reduced to half.
D. It becomes zero.