Countries with lower birthrates and longer average life spans typically face problems with
a. fighting increases in crime
b. higher rates of proverty and unemplyment
c. funding programs for senior citizens
d. the overcrowding of cities

Low birthrate means that fewer of a population have children. The sentence also states that there are more older people in an area. Therefore, the answer is B. Higher rates of poverty and unemployment are going to occur because the economy would fall without innovative young adults. Older people tend to focus in retirement, and the economy may fall because there is a lack of employed people.