4. GWD25-Q4.
Recent findings lend strong support to the theory that a black hole lies at the center of the Milky Way and of many of the 100 billion other galaxies estimated to exist in the universe.
A. that a black hole lies at the center of the Milky Way and of
B. that a black hole lies at the Milky Way’s center and
C. that there is a black hole lying at the milky Way’s center and
D. of a black hole lying at the Milky Way’s center and
E. of a black hole that lies at the center of the Milky Way and of(A)
我选了b，为什么选A | 
