Big Bang theory explains:

origin of Universe

The correct answer is option 1. origin of Universe.

The Big Bang theory explains the Origin of Universe. The Big Bang theory is the prevailing cosmological model that describes the early development and evolution of the universe. It proposes that the universe originated from a hot, dense state approximately 13.8 billion years ago and has been expanding and cooling ever since. According to this theory, all matter, energy, space, and time were compressed into an infinitely small point known as a singularity, which then rapidly expanded in an event called the Big Bang. The Big Bang theory provides a framework for understanding the large-scale structure and evolution of the universe, including the formation of galaxies, stars, and other cosmic structures.