Life originated how many years ago?

Origin of earth dated back around 4.6 billion year ago which makes options A and B incorrect as life originated only after origin of earth. The period of 4.6 billion year ago to 3.8 billion years ago is termed as Azoic era when the primitive earth conditions were too harsh to sustain any life form. During this period, the earth temperature cooled down and ocean and atmosphere were formed. The Archaeozoic era is marked by appearance of first life form in hot soup of primitive ocean which dates back around 4 billion years ago. The first life forms were prokaryotic chemoheterotrophic anaerobic organisms.