Concept:Population reduction aims to lower birth rates or increase out-migration.
Early marriage usually raises birth rates, so it does not help reduce population.
Explanation:Encouraging emigration reduces population because people leave the country.
Family planning helps couples have fewer children, which lowers population growth.
Sex education creates awareness about birth control and reproductive health, also reducing population.
Early marriage generally leads to a longer childbearing period and higher number of births.
Therefore, early marriage increases population rather than reducing it.
Answer:C. early marriage