Which region can you place a 3'd charge so that the net electrostatic force on it is zero? A -5 nC B . -8 nC C 1. positive charge in region A 2. positive charge in region B 3. positive charge in region C 4. negative charge in region A 5. negative charge in region B 6. negative charge in region C 7. the force on a third charge will not be zero in any region