Final answer:
The number of children that one generation must produce to be able to replenish its numbers is called the replacement level. Therefore, the correct option is C
Step-by-step explanation:
The number of children that one generation must produce to be able to replenish its numbers is called the replacement level. It is the fertility rate at which women average only enough children by the end of their reproductive years to replace themselves and their partners in the population. This rate is slightly greater than two because some children will never reach reproductive age or have children of their own.