Fossils of Prokaryotes Go Back __________ Billion Years

Question

Fossils of prokaryotes go back __________ billion years.
A)4.0 to 5.0
B)3.5 to 4.0
C)2.5 to 3.0
D)2.2 to 2.7

Accepted Answer

Fossils of prokaryotes have been found in rocks that are 3.5 to 4.0 billion years old. This suggests that prokaryotes were present on Earth at least that long ago.