In 1953 S. L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from preexisting non-living organic molecules. The primitive earth conditions created include:
a. low temperature, volcanic storms, atmosphere rich in oxygen
b. low temperature, volcanic storms, reducing atmosphere
c. high temperature, volcanic storms, non-reducing atmosphere
d. high temperature, volcanic storms, reducing atmosphere containing CH4, NH3 etc.