A) some complex molecules associated with living organisms can be synthesized by heating and cooling a solution of simple molecules and providing an electric spark. B) microbes will not grow in a nutrient broth that has been sterilized unless air is allowed to enter the vessel through an opening. C) microbes will grow spontaneously in a nutrient broth that has been sterilized and sealed. D) only some organisms can form spontaneously in nutrient broth. E) life began by chemical evolution.