GKFix MCQ Question

What is the main consequence of adding Eqs. (9.17) and (9.18) in the derivation?

• A. Obtaining a general equation (Eq. 9.19) relating object distance, image distance, and lens properties
• B. Eliminating the need for the thin lens approximation
• C. Proving that light rays are straight lines
• D. Making the lens opaque