What does the r in the acronym smart stand for

The number of brain synapses is believed to peak at

Time's up got my coins up, my bars up, soon we find 'em we gon' slide 'em, we lined 'em, straight reclined 'em pistol grip, i got all kinds of, i'm not your driver shot gon' hit him, he won't answer, i'm blowin’ ganja so much work, they call me old school, i remind ya that bisshhh you think you got is not you, where you find her? she a kickstand, a big fan, i get behind her then i slid it in, i win, i win, ayy

Which the following is a common trait in a four year college