Final answer:
The required number of children a generation must produce to sustain its population levels is called the replacement fertility rate, which is slightly over two children per woman to account for mortality and other factors. the correct option is a. the fertility rate.
Step-by-step explanation:
The number of children one generation must produce to replace itself is known as the replacement fertility rate. This rate typically exceeds two children per woman to account for children who may not survive to adulthood or who may not have children themselves.
The fertility rate, which is the actual number of children born to a woman throughout her lifetime, could be affected by various factors such as infant mortality rate and economic conditions. This rate contrasts with family size, which refers to the number of living children raised by parents in the same household.
To stabilize population size, the fertility rate must reach the replacement level, which compensates for mortality rates and ensures sufficient numbers to replenish the previous generation.