The theory that suggests the universe began from a singularity and underwent a period of rapid expansion (inflation) is the option A. Big Bang Theory.
This theory posits that the universe originated from an extremely hot and dense singularity approximately 13.8 billion years ago. After this initial singularity, the universe rapidly expanded in a process known as cosmic inflation. This theory is supported by various observations, including the cosmic microwave background radiation and the redshift of galaxies, which indicate that the universe is still expanding.
This is a variation of the inflationary model which suggests that inflation is a never-ending process, creating a multiverse of numerous "bubble universes." It extends the concept of inflation but doesn't necessarily describe the origin from a singularity.
This model proposes that the universe undergoes endless cycles of expansion and contraction (Big Bang followed by Big Crunch), but it does not focus on a singularity or a single inflation event as the origin.
This theory suggests that the universe has no beginning or end and that it maintains a constant average density as it expands. Matter is continuously created to form new stars and galaxies, keeping the universe's appearance consistent over time. It does not involve a singularity or inflation.
Therefore, the correct answer is A. Big Bang Theory.
