3. What concept is illustrated by the graph's “peaks” at ages 40-44 and 65-69? (A) An unbalanced dependency ratio
(B) Increasing crude birth rates over time
(C) Increasing life expectancy
(D) A baby boom and echo
(E) A need for more effective family planning in certain years?

Based on the graph, how is coal consumption likely to affect future generations? a. the higher our current rate of consumption, the less coal will be available in the future. b. current rates of consumption are irrelevant because new coal will form in the future. c. the lower our current rate of consumption, the more slowly coal will be replenished for the future. d. regardless of current rates of consumption, coal will always be available.