Which of the Following Is a Challenge Posed by Greater

Which of the following is a challenge posed by greater dependency ratios in the United States?

A) Younger people will not be able to find spouses.
B) Businesses and services targeted at younger people will fail.
C) The U.S. will not be able to produce enough doctors, on whom older people depend.
D) Public programs like Medicare and Social Security will have a smaller pool of younger people to provide revenue for older people.