The Cosmic Microwave Background Was Discovered by

Multiple Choice

The cosmic microwave background was discovered by

A) rocket-borne telescopes that also discovered X-ray sources in space.
B) the Voyager 2 spacecraft during one of its "coasting" periods between planetary encounters.
C) scientists testing a new antenna and receiver for satellite communications.
D) the Infrared Astronomical Satellite (IRAS) , which produced an all-sky infrared survey.