Dusty Is Six Credits Away from Completing His Bachelor's Degree

Dusty is six credits away from completing his bachelor's degree in an online program.In his current online class,he is the one who starts the majority of threads on the discussion boards.Also,other students frequently send him e-mails asking his opinion about the best way to complete assignments.Dusty has the network role of a ______.

A) gatekeeper
B) bridge
C) liaison
D) star