Question ID:PT31 S3 Q25 Passage:In our solar system only one of the nine planets‚ Earth‚ qualifies as fit to sustain life. Nonetheless, using this ratio, and considering the astonishingly large number of planetary systems in the universe, we must conclude that the number of planets fit to sustain some form of life is extremely large. Stem:The argument is questionable because it presumes which one of the following without providing justification? Correct Answer Choice:BChoice A:If a planet is Earthlike, then life will arise on it. Choice B:Our solar system is similar to many other planetary systems in the universe. Choice C:The conditions necessary for life to begin are well understood. Choice D:Life similar to Earth's could evolve under conditions very different from those on Earth. Choice E:Most other planetary systems in the universe have nine planets.