Please answer the following question: Answer the following question given this paragraph: The Precambrian Supereon (4.6 billion544 million years ago) is the first major division of the geologic time scale. The first living cells may have evolved around 4 billion years ago. By 1 million years ago, the first multicellular eukaryotes had evolved. The Precambrian ended with the first of six mass extinctions that occurred during Earth's history. Q: The first living cells may have evolved around how long ago? Choices: - 900,000 years - 6 billion years - 2.2 billion years - 4 billion years A:
A:
4 billion years