Three charges QA = -2.0 \mu C, QB = 6.0 \mu C, and QC = -4.0 \mu C are located along the y-axis at yA = -4.0 cm, yB = 0, and yC = 2.0 cm respectively. Calculate the electric potential at the point x = 6.0 cm on the x-axis. Select one: A. -0.41 \times 105 V B. 0.81 \times 105 V C. -0.81 \times 105 V D. 0 E. 0.41 \times 105