GKFix MCQ Question

What is the correct expression for the work done in bringing q₂ into the field of q₁?

• A. q₁ × q₂ × r₁₂
• B. (1/(4πε₀)) × (q₁/r₁₂)
• C. q₂ × [ (1/(4πε₀)) × (q₁/r₁₂) ]
• D. (q₁ + q₂)/(4πε₀r₁₂)