Cocaine sometimes produces extreme alertness and an exaggerated awareness of environmental stimuli. This is because one of its effects is to enhance the activity of the neurotransmitter that helps prepare the body for stressful situations, namely: A. serotonin B.endorphins C.acetylcholine D.Norepinephrine Solution D) NOREPINEPHRINE.....it is the stressful situation harmone ...cocaine blocks neurotransmiter transportersinthe brain hence increasing the concentration of norepinephrinein the synapse ....