Concept:Infant mortality means the death of infants before their first birthday, so it is counted within a country's death rate.
Explanation:A country's population growth is determined by births, deaths, and migration.
Infant mortality records the number of infants who die in a given period.
Because these deaths are also deaths in the population, they are added to the total number of deaths.
Hence, infant mortality is a component of the death rate and not of the fertility rate, immigration rate, or net migration.
Answer:D. Death rate.