Which of the following is the main evidence of life in early universe?

a) Dinosaur fossils

b) Rock impressions

c) Remains in amber

d) Photosynthetic bacteria

Photosynthetic bacteria are the main evidence of life in early universe. These bacteria most likely produced oxygen, which was a waste product that was caused by photosynthesis. As the oxygen levels increased, many early forms of life were poisoned. This caused the evolution of new organisms that were able to utilize oxygen for breathing or respiration.