The idea of spontaneous generation is an obsolete theory that states that living organisms can originate from inanimate objects. Other common examples of spontaneous generation were that dust creates fleas, maggots arise from rotting meat, and bread or wheat left in a dark corner produces mice. The theory of spontaneous generation was hotly debated for hundreds of years. During this time, many experiments were conducted to both prove and disprove the theory. In 1668, Francesco Redi published the first set of experiments challenging spontaneous generation. In these experiments, he demonstrated that maggots arise from the eggs of flies rather than directly from rotting meat. He did so by taking several jars and placing raw meat inside of them. Half the jars he left open to the environment, and the other half, he covered with gauze. John Needham, however, was not convinced. He argued that Redi did not fully disprove the theory of spontaneous generation. Needham maintained that while spontaneous generation did not occur in larger organisms, for smaller organisms, it could still take place under the right circumstances. In 1745, he set out to prove this by boiling broth in a flask, leaving it open to cool and then sealing it. In several days' time, the broth was teeming with bacteria and mold. He claimed that this was proof of the existence of spontaneous generation for microorganisms.
So the correct option is 'origin of life from non-life'.