“Science is supposed to be about things that are observable. That is, science can probe only things that we can detect with our five senses. Science also must be repeatable. This means that when an experiment or observation is repeated, we get the same results. These restrictions on science have led to what we call the scientific method, the general rules that we follow in doing science. The scientific investigation of the origin of life presents us with at least two problems. First, since life began before people were around, we hardly can observe the process. Second, since the origin of life appears to have been a unique event, we hardly can repeat it. …”\
My Comment: Your option four, “Life was seeded from space.” Should be eliminated as a potential answer to the question posed in the title of the thread, “Is the Origin of Life a Scientific Question?” because it does not even attempt to explain the origin of life. It simply pushes the question from our planet to the rest of the universe.
Now, since you have already eliminated options one and two, “Life on earth arose spontaneously,” and “Life on earth has always existed,” then the only remaining alternative for the origin of life is the third one: “Life on earth came about through a supernatural act of creation by an intelligent Being.”