Microbial Cells First Evolved on Earth Approximately ________ Billion Years

Question

Microbial cells first evolved on Earth approximately ________ billion years ago.
A) 1.6 to 1.8
B) 3.8 to 4.3
C) 5.4 to 5.6
D) 7.0 to 7.2

Accepted Answer

Microbial cells first evolved on Earth approximately 3.8 to 4.3 billion years ago, as evidenced by the oldest known fossils of microbial life.