In what way are microorganisms used in the production of coffee?

A) Extracts of coffee beans are fermented by bacteria.
B) Extracts of coffee beans are fermented by yeast.
C) Extracts of coffee beans are first fermented by yeast. Fermentation waste products released by the yeast are then converted in different products by aerobic bacteria.
D) Microorganisms that grow naturally on coffee beans provide the coffee with desirable flavors.
E) Bacteria are used to remove the coating of coffee beans prior to roasting.