The Appearance of Complex Multicellular Animals in the Fossil Record

The appearance of complex multicellular animals in the fossil record:

A) coincides with abundant levels of oxygen in the atmosphere and ocean.
B) occurred at about the same time as the appearance of land plants.
C) occurred soon after the appearance of simple multicellular organisms.
D) occurred after the appearance of complex multicellular fungi.
E) coincides with time period when oxygen first began to accumulate in the atmosphere.