Oil formed because:________
A. Leaves, twigs, and tree trunks decomposed under conditions of heat, pressure, and low oxygen.
B. Tiny algae and plankton decomposed under conditions of heat, pressure, and low oxygen.
C. The decomposition of organic material remained aerobic (lots of oxygen) for a long time.
D. Large sauropod-type dinosaurs decayed in swamps.
E. The temperature reached a minimum of 1,000°C.