This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Rhodopsin has a peak sensitivity to light of wavelength: 
Select and explain. 
A. 100 nm, B. 355 nm, C. 505 nm, D. None of the above
C: 505 nm
Answer: C: 505 nm 
Explanation: The photosensitive pigment in the rods is called rhodopsin (visual purple). Its opsin is called scotopsin. Rhodopsin has a peak sensitivity to light at a wavelength of 505 nm. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 12.