The overall rate

The overall rate of emphysema has declined 15 percent over the last 15 years in region A. During that period, the total cost of care for emphysema sufferers in region A, after accounting for inflation, declined by two percent per year until eight years ago, at which time it began increasing by approximately two percent per year. Now the total health care cost for treating emphysema is approximately equal to what it was 15 years ago.

Which one of the following best resolves the apparent discrepancy between the incidence of emphysema in region A and the cost of caring for emphysema sufferers?

A . The overall cost of health care in region A has increased by seven percent in the last 15 years, after accounting for inflation.
B. Improvements in technology have significantly increased both the cost per patient and the success rate of emphysema care in the past 15 years.
C. About seven years ago, the widespread switch to health maintenance organizations halted overall increases in health care costs in region A after accounting for inflation.
D. The money made available for research into the causes and cures emphysema had been declining for many years until approximately eight years ago, since which time it has shown a modest increase.
E. Beginning about nine years ago, the most expensive-to-treat advanced cases of emphysema have been decreasing in region A at a rate of about five percent per year.

My Ques: Please explain this premise and the solutions. It was very hard for me to do it within 2 mins.