Four +600-µC Point Charges Are at the Corners of a Square

Multiple Choice

Four +6.00-µC point charges are at the corners of a square 2.00 m on each side. What is the electric potential of these charges, relative to infinity, at the center of this square? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

A) 76.4 kV
B) 38.2 kV
C) 306 kV
D) 153 kV
E) 61.0 kV