What do you understand by the concept of 'population momentum'?

Refers to the estimated number of years that an average person is expected to survive.

Refers to the proportion of persons in different age groups relative to the total population.

Is a measure comparing the portion of a population which is composed of dependents with the portion that is in the working age group, generally defined as 15 to 64 years.

Refers to a situation, where a large cohort of women of reproductive age will fuel population growth over the next generation, even if each woman has fewer children than previous generations did.