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: Unknown
Neurotransmitter employed by rods and cones is 
Select and explain. 
A. Dopamine, B. Serotonin, C. Glutamate, D. Nitric oxide
C: Glutamate
Answer: C: Glutamate 
Explanation: None