The correct option is D Black Holes
D)
ASTRO-H satellite has been developed by the Japan Aerospace Exploration Agency (JAXA) in cooperation with National Aeronautics and Space Administration (NASA) and others. It will orbit earth at an altitude of about 580 kilometres and observe X-rays emanating mainly from black holes and galaxy clusters. It is cylindrically shaped and is 14 meters long and weighs 2.7 tonnes. It is the heaviest scientific satellite Japan has worked on. It will help unravel the mysteries of the universe. The satellite has been equipped with four X-ray telescopes and two gamma-ray detectors and is designed to capture X-rays that cannot be detected on Earth because the planet’s atmosphere absorbs them