Read this excerpt from "A Visit from the Goon Squad."

Whatever the reason, a swell of approval palpable as rain lifted from the center of the crowd and rolled out toward its edges, where it crashed against buildings and water wall and rolled back at Scotty with redoubled force, lifting him off his stool, onto his feet (the roadies quickly adjusting the microphones), exploding the quavering husk Scotty had appeared to be just moments before and unleashing something strong, charismatic, and fierce. Anyone who was there that day will tell you the concert really started when Scotty stood up.

How does the author portray Scotty in this excerpt?
A. His confidence is transformed by the crowd’s response.
B. His musical ability is improving as he performs.
C. His anger is unleashed by the chaos of the crowd.
D. His excitement is shown by his moves on stage.