Natality is

• A
  The number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration.
• B
  The number of births during a given period in the population that are added to the initial density.
• C
  The number of deaths in the population during a given period.
• D
  The number of individuals of the population who left the habitat and gone elsewhere during the time period under consideration.