Task: Question Answering
Input (English): Question: The reinforcement circuit can be activated by electrical stimulation of the mesolimbic system, originating in the ventral tegmental area and projecting: 
 Options:  <1> To the hippocampus, inhibiting the release of dopamine. <2> To the nucleus accumbens, causing release of dopamine. <3> To the prefrontal cortex, stimulating the release of glutamate. <4> A mesencephalic reticular formation, causing release of glutamate. <5> To the pituitary, inhibiting the release of dopamine.
Output (English): 2