GKFix MCQ Question

In the expression for induced emf in coil 1, ε₁ = –L₁(dI₁/dt) – M₁₂(dI₂/dt), what does M₁₂ represent?

• A. Self-inductance of coil 2
• B. Resistance between coils
• C. Capacitance between coils
• D. Mutual inductance between coil 1 and coil 2