Question

HELPPPPP WILLL GIVE BRAINLIEST!!!!!RATE!!!!! AND THANKS!!!!! EASY BUT IM DUMB!!!!


What evidence BEST supports the presence of atmospheric oxygen 2.7 billion years ago?
A) organic material in meteorites
B) layered iron rust in rocks
C) fossils found in stomatolites
D) carbon 14 in plants

Answer 1

Answer:

c

Explanation:

Answer 2

Answer:

D) carbon 14 in plants

Explanation:

Plants fix atmospheric carbon during photosynthesis, so the level of 14C in plants and animals when they die approximately equals the level of 14C in the atmosphere at that time. However, it decreases thereafter from radioactive decay, allowing the date of death or fixation to be estimated.