Isotopic Evidence Shows That Photosynthetic Life Existed on Earth as Early

Isotopic evidence shows that photosynthetic life existed on Earth as early as _________ billion years ago, but the oldest fossil evidence of life on Earth is about __________ billion years ago.

A) 4.5; 3.7
B) 4.5; 3.5
C) 3.7; 3.5
D) 3.7; 2.5