Question: Approximately 14,000 years ago, the climate in North America began to warm rapidly. At the same time, human hunters migrated to the continent. Which of these most likely resulted from a combination of these two factors?

  Options: 
 A. a reduction in the rate of species change
 B. an increase in the rate of large mammal extinctions
 C. an increase in the amount of interspecies cooperation
 D. a reduction in the total number of small parasitic insects
Answer: B