Physiology During the dark phase of visual cycle, which form of vitamin A combines with opsin to make Rhodopsin: A All trans-Retinaldehyde B all trans-Retinol C 11-cis-Retinaldehyde D 11-cis-Retinol 💡 Explanation During the dark phase of visual cycle, which form of vitamin A combines with opsin to make Rhodopsin: ✓ Correct Answer: C. 11-cis-Retinaldehyde