Conducting sphere A has 4 x 1014 electrons and equally many protons. It is touched by identically sized conducting sphere B, which has 6 x 1014 electrons and 4 x 1014 protons. What is the charge on sphere A after the touching process?
a. -2 x 1014
b. -1 x 1014
c. 0
d. +1 x 1014