Four Point Charges Q₁ = -1 $\mu$ C, Q₂ = 2 $\mu$

Four point charges q₁ = -1 $\mu$ C, q₂ = 2 $\mu$ C, q₃ = 3 $\mu$ C, and q₄ = 4 $\mu$ C are located at the corners of a square whose side s = 1.00 m. The electrostatic potential energy of this system of charges is

A) 0.140 J.
B) 0.176 J.
C) 0.286 J.
D) 0.337 J.
E) 0.492 J.