The correct answer is: A) GABA
GABA or γ-aminobutyric acid is a type of amino acid that's found in proteins. It is the main inhibitory neurotransmitter in the brain which means that GABA reduces neuronal excitability throughout the nervous system. GABA binds to its receptors that are located on the neuron’s plasma membrane. This binding causes the opening of ion channels that transport chloride ions into the cell or potassium ions out of the cell.
