In his public speaking class, Sam presented an informative speech on hurricanes

He described the origins of hurricanes, how they develop, which areas of the earth are prone to hurricanes, how hurricanes are rated, the damage they do, and what to do when one hits. The speech was dry and the class was bored. From this description, what was Sam's mistake?
A) poor topic selection
B) lack of appropriate research
C) failing to narrow his topic
D) incoherent main points

C