When the Isotropy of the Cosmic Microwave Radiation Was First

Multiple Choice

When the isotropy of the cosmic microwave radiation was first realized, what effect did this discovery have on the contemporary theories of cosmology?

A) The discovery was a great support for the Big Bang cosmology that predicts this isotropy.
B) The discovery was a great support for the steady-state cosmology that predicts this isotropy.
C) The discovery was a great problem because it was prohibited by all the main cosmologies.
D) The discovery was a puzzle because the Big Bang cosmology does not predict this isotropy, although it does not prohibit it either.