Answer:
B.Cosmic microwave background radiation and primordial helium gas were found.
C.The redshift of light from distant stars and galaxies indicates that the universe is still expanding.
Explanation:
The theory of Big Bang describes the beginning of the universe. According to the theory, all the matter was confined in a single point which started expanding at the big bang. in the initial stage, the universe was opaque so that no radiation could escape.
Cosmic microwave background radiation is the remnant radiation after the initial stage of the universe. It was detected from all the directions in the sky. The average temperature of the CMB is about 3 K.
The measurement of red-shift from distant stars and galaxies indicates the expanding universe.
Thus, the above two evidences support the big bang theory.
