Carbon Isotope Evidence from Rocks Found on an Island Off

Multiple Choice

Carbon isotope evidence from rocks found on an island off the coast of Greenland, although controversial, suggests that life may have

A) existed and was well established by3.4 to 3.5 billion years ago
B) originated about 3.4 billion years ago
C) existed 3.85 billion years ago
D) originated when the Earth formed 4.6 billion years ago