Final answer:
Developing countries have more youthful populations than industrial countries due to higher birth and fertility rates. The age distribution in these countries features a higher proportion of children and young adults.
Step-by-step explanation:
Generally, because of higher birth and fertility rates, developing countries have more youthful populations than industrial countries. The correct answer is A. youthful. Developing countries, or economically underdeveloped countries, tend to have a higher proportion of youth and young adults in their populations. This is in contrast to economically developed countries, which typically have a more even distribution of age groups and are approaching a demographic situation where the elderly will form a larger share of the population.
Age structures in developing countries show a larger ratio of very young individuals compared to the number of elderly individuals. Over time, by about 2050, it is expected that the elderly populations in these low-income countries will also increase considerably, impacting the standard of living for both the young and the old. Meanwhile, many high-income nations are already seeing a significant percentage of their populations entering into old age.