Which statement about the cosmic microwave background isnottrue? a) it is the result of a mixture of radiation from many independent sources, such as stars andgalaxies. b) it is thought to be radiation that began its journey to our telescopes when the universe wasabout 380,000 years old. c) with the exception of very small variations, it appears essentially the same in all directions inwhich we look into space. d) its spectrum corresponds to a temperature of just under 3 degrees above absolute zero.