Final answer:
The availability of abundant food and resources did not result in many Indian deaths on the Great Plains; it was factors like the spread of diseases, violence with settlers, and disruption of food sources like the bison herds.
Step-by-step explanation:
The question relates to the factors that resulted in many Indian deaths on the Great Plains. We can identify numerous contributors to the decline in Native American populations, including the spread of diseases brought by Europeans, violence and conflicts with settlers, and the impacts of European livestock on indigenous crops and land. However, the availability of (option 4) 'abundant food and resources' is not historically documented as a factor that led to their deaths. In fact, the disruption of buffalo migration patterns by railroads and the confinement of Native Americans to reservations greatly limited their access to traditional food sources.
Moreover, Plains groups transitioned from agriculturalists to nomadic hunter/gatherers for several reasons such as the reintroduction of the horse to North America, but not because of an over-abundance of resources. In truth, the reverse occurred; their food sources, mainly the bison, were decimated due to overhunting and habitat loss instigated by westward expansion and settlement.