In the Early 1960s, Physicists Named Penzias and Wilson Detected

Multiple Choice

In the early 1960s, physicists named Penzias and Wilson detected a persistent noise at a wavelength of 1 mm in their radio telescope that came from all directions in the sky due to:

A) synchrotron emission from the Crab Nebula
B) emission from newly formed stars in the Orion Nebula
C) cellphone usage
D) photons left over from the Big Bang
E) television and radio broadcasting