Final answer:
Scientists can be sure that the meteorite that formed the Meteor Crater near Flagstaff was composed of iron by identifying the presence of nickel-iron fragments. The correct answer is D) By identifying the presence of nickel-iron fragments.
Step-by-step explanation:
Iron meteorites are composed primarily of nickel and iron, and the presence of nickel-iron fragments provides strong evidence for the composition of the meteorite. Iron meteorites represent a much higher percentage of finds than falls because they are more likely to survive the journey through Earth's atmosphere without burning up completely. This is because iron is a very dense and strong material, which allows iron meteorites to withstand the forces of atmospheric entry and impact with the Earth's surface.
It is more useful to classify meteorites according to whether they are primitive or differentiated rather than whether they are stones, irons, or stony irons because primitive and differentiated meteorites provide information about the processes and materials present in the early solar system. Primitive meteorites are relatively unchanged since their formation, while differentiated meteorites have undergone some level of geological processing.