After how many years of formation of Earth did life appear?

The appearance of life on Earth is estimated to have occurred approximately 3.5 to 4 billion years ago, following the formation of the planet around 4.5 billion years ago. This means life emerged roughly 500 million years after the Earth's formation.

Considering this timeline, the approximate 500 million years aligns with evidence from fossil records and geological studies that indicate the earliest forms of life, such as single-celled organisms, began to appear in the primordial oceans. This significant period allowed the Earth to cool and stabilize, creating suitable conditions for life to develop.

The timeframe presented in the other options does not accurately reflect the evidence collected by scientists regarding the early history of Earth and the emergence of life. The development of life took place after a significant evolutionary period where the planet underwent various geological and atmospheric changes, which were essential for supporting life as we know it today.