Recent discoveries of microscopic fossils have extended the known history of life to about:
A)1 billion years ago.
B)2 billion years ago.
C)3.5 billion years ago.
D)4.5 billion years ago.

Question

Quizplus · Accepted Answer

Recent discoveries of microscopic fossils have extended the known history of life to about 3.5 billion years ago, which is when the earliest known life forms, such as stromatolites, are believed to have existed.

Recent Discoveries of Microscopic Fossils Have Extended the Known History