Our solar system is thought to have started with the birth of our Sun, which formed from a cloud of interstellar dust and gas. This cloud condensed and eventually collapsed from its own gravitational pull. The heat and pressure built up, forming a protostar. Eventually nuclear fusion began. Planets formed from remaining dust and gas orbiting the protostar.
This explanation best describes _____.
A. The Nebular Theory
B. The Big Bang Theory
C. The Inflation Theory
D. The Condensation Theory

Nebular theory explains the formation of our solar system. It explains the birth of Sun from cloud of dust and gas. The beginning nuclear fusion after condensation and collapse of this cloud and formation of planets.

The big bang theory describes the theory of beginning of universe.

The inflation theory proposes the rapid expansion of universe in first few moments of the formation of universe.

Condensation theory explains the arrangement of planets and orbits about the Sun in our solar system.

Hence, the correct option is A.