Astronomers have only been able to speculate about the nature of black holes for many years. Now astronomers have had their first glimpse at the mysterious region near a black hole at the heart of a distant galaxy. Using ______________, astronomers were able to gain more information about black holes, by recording invisible wavelengths emitted from celestial bodies as well as these subatomic particles (pictured) jetting away from the black hole. A) space probes. B) radio telescopes. C) X-ray telescopes. D) satellite imaging.