One of the great challenges of cosmology today is to --- A
determine the amount of matter in the Universe
B
find intelligent signals emanating from outer space
С
look backward in time to before the Big Bang
D
locate wormholes to help define the structure of the Universe

Steady-state theory, in cosmology, a view that the universe is always expanding but maintaining a constant average density, with matter being continuously created to form new stars and galaxies at the same rate that old ones become unobservable as a consequence of their increasing distance and velocity of recession.

Cosmic inflation is a faster-than-light expansion of the universe that spawned many others. ... Cosmic inflation solves these problems at a stroke. In its earliest instants, the universe expanded faster than light (light's speed limit only applies to things within the universe).