GKFix MCQ Question

What is the formula for the critical angle (θc) between two media?

• A. θc = cos⁻¹(n₁/n₂)
• B. θc = tan⁻¹(n₂/n₁)
• C. θc = sin⁻¹(n₂/n₁)
• D. θc = n₁/n₂