Final answer:
The solar system formed about 4.5 billion years ago from a collapsing gas and dust cloud called the solar nebula, leading to the formation of the Sun and planets. Hence, correct option is A. a giant collision ocurred between two asteroid belts
Step-by-step explanation:
Formation of the Solar System:
About 4.5 billion years ago, our solar system began to form. The process started when a nearby star exploded, sending a shock wave through a cloud of gas and dust and causing it to collapse under its own gravity. This cloud, called the solar nebula, spun faster as it contracted, and most of the material concentrated at the center to form the Sun. Around this central mass, smaller concentrations of matter began to coalesce into what would become the planets, their moons, and other solar system debris.
The giant planets, like Jupiter and Saturn, started as solid cores that attracted and held gas from the solar nebula. Their enormous gravity influenced the orbits of objects throughout the solar system, possibly causing a period called the 'heavy bombardment' where numerous impacts shaped the planetary surfaces.
All these events are part of a broad scientific consensus regarding solar system formation, which also helps explain the presence of other planetary systems in the universe.