Answer:
a. The universe is continuing to expand.
b. The universe stretched from a single point.
Explanation:
An explanation by the astronomers of how the universe was formed or began is referred to as the big bang theory. They posited that the universe stretched from a single point and then expanded to how it is right now.
Basically, it was stated by the astronomer known as Georges Lemaître.
The statements which best describe the principles of the big bang theory are;
I. The universe is continuing to expand.
II. The universe stretched from a single point.