खालीलपैकी कोणत्या देशाने जगातील सर्वात शक्तिशाली GEO हेरगिरी उपग्रह ‘Gaofen 4’ प्रक्षेपित केला?

China launched Gaofen-4 in December 2015. It is a high-resolution Earth observation satellite in geostationary orbit, described as the world's most powerful GEO imaging satellite.