If the Equilibrium Separation of Na⁺ and F^- Ions Is $\times$

If the equilibrium separation of Na⁺ and F^- ions is 0.193 nm,then their electrostatic potential energy (with U = 0 at infinite separation) must be approximately

A) -1.19 $\times$ 10^-18 J
B) 1.19 $\times$ 10^-18 J
C) 7.42 J
D) -7.42 J
E) 4.64 $\times$ 10¹⁹ J