Three negative charges of equal magnitudes are positioned along the x-axis at x = -a, x=0, and x = +a respectively. The charge located at x=0 is moved away along the y-axis to a position (x, y) = (0, +a). How does the potential energy of the system of charges change as a result?
a. The potential energy decreases.
b. The potential energy stays the same.
c. The potential energy increases.
d. The potential energy may increase or decrease depending on the magnitude of the charges.
e. More information is needed to answer the question.