15. Two tiny conducting balls of identical mass m and identical charge q hang from nonconducting threads of length L. Assume that θ is small, then the equilibrium separation x is approximately: (A)q²L/(4πε₀mg) (B)[q²L/(4πε₀mg)]1/2 (C)[2q²L/(πε₀mg)]1/2 (D)[q²L/(2πε₀mg)]1/3 (E)[3q²L/(πε₀mg)]1/3