What condition would have made the primitiveatmosphere of Earth more conducive to the origin of life than thepresent one? The primitive atmosphere
Choose one answer.
    a. had a layerof ozone that shielded the first fragile cells.    
    b. removedelectrons that impeded the formation of protobionts.    
    c. may have beena reducing one that facilitated the formation of complex substancesfrom simple molecules.    
    d. had moreoxygen than the modern atmosphere, and thus it successfullysustained the first living organisms.    
    e. had less freeenergy than the modern atmosphere, and thus newly formed organismswere less likely to be destroyed.