At the pr firm where gerald works, everyone considers him to be very good with his work and depends heavily on his knowledge to the organization to solve its problems. gerald is often seen teaching interns a simpler way to present an article, project managers with scheduling, and even the ceo often asks him for his opinion on important matter because of his experience and skill. gerald's specialized knowledge depicts his a) expert power b) coercive power c) legitimate power d) referent power e) reward power