This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
The amino acid which on decarboxylation gives rise to a product with potent vasodilator propeies is 
Select and explain. 
A. Histidine, B. Arginine, C. Glutamate, D. Aspaate
A: Histidine
Answer: A: Histidine 
Explanation: Neurotransmitters obtained from amino acids Amino acidNeurotransmitterNature/FunctionGlutamateGABAInhibitory neurotransmitterHistidineHistaminePotent vasodilator, bronchospasm, stimulates gastric acid secretionTyrosineTyramine, Epinephrine, Norepinephrine, Dopamine, DOPATryptophan5-hydroxytryptamine (Serotonin)Regulation of pleasures related to motivation & emotional arousal. Regulate appetite, sleep, memory and learning, temperature, mood. MelatoninConnected with sleep-wake cycle and biological rhythm. Blocks MSH and ACTH secretions CysteineTaurineInhibitory neurotransmitterGlycineGlycineInhibitory neurotransmitterGlutamateGlutamateExcitatory neurotransmitterAspaateAspaateExcitatory/Inhibitory neurotransmitterArginineNitric oxideVasodilator