PLEASE HELP I feel like the answer is number 4 but im not sure.

What was the key factor in creating the Earth's early atmosphere?



respiration of single-celled organisms


photosynthesis of land plants


violent storms


outgassing by volcanoes

Respuesta :

I think it is also 4

Answer: outgassing by volcanoes

Explanation:

sorrry im 3 almost 4 years late :U