Background extinction is a measure of the ____.

Background extinction is a measure of the ____.
  a. rate of species turnover at the end of geological eras
  b. number of species that suffer extinction at the beginning of geological eras
  c. steady rate of species turnover within a lineage throughout most of their evolutionary history
  d. lowest rate of species turnover within a lineage observed within a geological era
  e. animals that appear in the dense forest

Question 2

When new species move into a wide range of habitats during microevolution, it is known as ____.
  a. adaptive radiation
  b. natural selection
  c. genetic drift
  d. mass extinction
  e. minor extinction