What Did the Cosmic Microwave Background Tell Cosmologists About the Early

Multiple Choice

What did the cosmic microwave background tell cosmologists about the early universe?

A) Nothing; it is a product of the black hole in the center of our own Galaxy.
B) the horizon problem, in that the microwave background is almost too isotropic
C) the discovery of dark energy and its role in accelerating the universe
D) the discovery of relativistic redshifts and the Big Bang
E) The dark matter in the universe is mostly baryonic in nature, for a closed Big Bang.