Which of These Factors Will Create a Rapid Increase in the Number

Which of these factors will create a rapid increase in the number of people over the age of 65 in the years 2010 to 2030?

A) During these years the baby boomers will reach age 65.
B) Individuals in this age category are taking better care of themselves.
C) Medical technology has allowed people to live longer.
D) People over age 65 are living an average of 25 years longer.