GKFix MCQ Question

How is work calculated when moving a mass from r1 to r2 against gravity in variable field?

• A. W₁₂ = mg(r₂ – r₁)
• B. W₁₂ = F × r
• C. W₁₂ = –GMm (1/r₂ – 1/r₁)
• D. W₁₂ = GMm (r₂ – r₁)