Question

The researchers of which country has showed that dark matter is not made up of tiny black holes?
A. India
B. United States
C. China
D. Japan

Answer 1

I think it's opt B
coz its researched by NASA of America

Answer 2

Researchers led by Kavli Institute for the Physics and Mathematics of the Universe in Japan has put a theory speculated by the late Stephen Hawking to its most rigorous test to date, and their results have ruled out the possibility that primordial black holes smaller than a tenth of a millimeter make up most of dark matter. They used the gravitational lensing effect to look for primordial black holes between Earth and the Andromeda galaxy.