The correct answer is - the ocean animals deposited in its layers.
The sedimentary rock on the image is clearly an organic sedimentary rock because it contains fossils of marine animals. This type of sedimentary rocks form when sediments and organic matter come in contact, are merged, or rather naturally cemented so they are stuck together, and the end result is a sedimentary rock with organic matter involved in its composition. The organic sedimentary rocks are much more common in places where there was once a marine life, and much rarer with organic matter from terrestrial animals in it, though there are some rich deposits from that type in certain places as well.
The most surprising thing about the universe is that it we don’t know when it will end and it could end at any point in time. The most surprising fact about our galaxy is that it would take around 26,000 years to get out of it.
Spontaneous generation was a (refuted) theory that some forms of life can arise from inorganic matter.
Louis Pasteur refuted it in a series of experiments, in which he boiled different matter (grape juice, broth) which would kill all the bacteria and let it stay for a long time to see if it would develop life (he also had a control condition in which he let the boiled liquid interact with the outside words, and those would develop bacterial life).