During the First Emergence of Life,the Atmosphere was ____

Question

During the first emergence of life,the atmosphere was ____.  
A) high in oxygen, high in carbon dioxide
B) high in hydrogen, low in oxygen
C) changing from anaerobic to aerobic
D) aerobic
E) high in oxygen, low in carbon dioxide

Accepted Answer

During the first emergence of life, the atmosphere was high in hydrogen and low in oxygen. It is believed that the early atmosphere of earth lacked oxygen and that the first living organisms were anaerobic, which means they did not require oxygen to survive. Therefore, the answer is B- high in hydrogen, low in oxygen.