The Teapot Dome oilfield in Wyoming generally produces two types of crude oil: a light, brown oil that comes from the shallow Shannon formation and the heavy, black oil is found in the much deeper Tensleep formation.

A. formation and the heavy, black oil is found

B. formation, a heavy, black oil is found

C. formation while a heavy, black oil is

D. formation and a heavy, black oil found

E. formation, a heavy, black oil