Which of the Following Statements About Gamma Ray Bursts Is

Which of the following statements about gamma ray bursts is not true?

A) Gamma ray bursts are among the most luminous events that ever occur in the universe.
B) The events responsible for gamma ray bursts apparently produce only gamma rays,and no other light that we can hope to detect.
C) Gamma ray bursts were originally discovered by satellites designed to look for signs of nuclear bomb tests on Earth.
D) Based on their distribution in the sky,we can rule out a connection between gamma ray bursts and X-ray binaries in the Milky Way Galaxy.