In order for the human population to achieve zero population growth, which of the following must occur?

Zero population is the condition where the birth rate and the death rate are equal. The population in this stage is stabilised. To achieve such condition the pre-reproductive individuals count must either equal or less than the reproductive individuals. If the post reproductive members are more than reproductive it is a declining population having death rate higher than birth rate.If the reproductive members are fewer than pre-reproductive members, the population will not be rising as again death rate is higher than birth rate.