According to the text,what conclusion can be drawn from Eli Whitney's cotton gin and Thomas Edison's light bulb?

A) Inventors are often lone wolves whose inventions come to fruition through a process of trial and error.
B) Inventions often spring fully formed into an inventor's mind.
C) Inventions are often a result of the work of a group of different people who made improvements over a long period of time.
D) Products are often attributed to individuals who had little or nothing to do with their invention.