This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
Which of the following is true about colour vision 
Select and explain. 
A. Independent of wavelength of light, B. Depends on intensity discrimination, C. Involves opponent colour cells, D. Minimum at fixation point
C: Involves opponent colour cells
Answer: C: Involves opponent colour cells 
Explanation: Opponent theory for colour vision is proposed by Hering This theory states that the three primary colours red, blue and green oppose one another so that the opponent processing cells can't detect the presence of both colours at the same time Neurotransmitter stored in rods and cones is glutamate Ref: Ganong 25th ed/page 191