How does the idea of spontaneous generation tie in to our current understanding of the origin of life?

Spontaneous generation is a concept of the origin of life that can be traced back to the theories of Greek philosophers Aristotle and Plato and persisted through the Enlightenment Period. While some Enlightenment Period scientists experimented to show that life could arise even under controlled conditions,  their methods were not sanitary and microbial contamination of the containers used gave dubious results. it was Louis Pasteur who is generally credited with refuting the idea due to his more advanced and precise control of starting conditions that revealed that no life arose from non-life. This strongly established that life cannot arise from non-life.

Today, we have similar superstition by some naturalists who posit that natural processes are capable of producing living entities, whether it is SETI searching for extraterrestrials, NASA astrobiologists searching for aliens and panspermia, or other life enthusiasts similarly inclined.

Currently, the term abiogenesis is used by naturalists to detail the emergence of life from non-life,and has failed miserably to do so. It is very similar to the spontaneous generation idea that was disproven and lost favor in the 1800's. The current understanding strongly favors abiogenesis because it ideologically fits the belief system that all reality is the result of natural processes and forces, but there is not evidence of its validity, not even at the simplest biochemical levels.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

request for reexamination