Estimations Calculated Using the Rule of 70

Estimations calculated using the rule of 70:

A) make it easier to appreciate how small differences in growth rates can add up to huge differences in income over time.
B) make it easier to appreciate how big differences in growth rates are needed to create any real difference in income over time.
C) are simple to use, but make it difficult to see the relationship between growth rate and income over time.
D) are simple to use, but give estimates that have been proven wrong in recent decades.