In 1975, the number of high school dropouts in a country was 5216 thousand. By 2003, this number had decreased to 3120 thousand. Find and interpret the average rate of change per year in the number of high school dropouts. Select the correct choice below and fill in the answer boxes to complete your choice. (Round to the nearest tenth as needed.) A. The average rate of change is about thousand each year. The number of high school dropouts decreased thousand each year from 1975 to 2003. by an average of about B. The average rate of change is about thousand each year. The number of high school dropouts decreased by an average of about thousand in the year 2003. OC. The average rate of change is about by an average of about thousand each year. The number of high school dropouts increased thousand in the year 2003. OD. The average rate of change is about by an average of about thousand each year. The number of high school dropouts increased thousand each year from 1975 to 2003.