Final answer:
The average rate of change in sales, in millions of dollars per year, is approximately $1360 million.
Step-by-step explanation:
To find the average rate of change, we need to calculate the difference between the total amount spent in 2006 and 2003, and then divide it by the number of years between the two years. So, the average rate of change is:
Average rate of change = (5705 million - 1590 million) / (2006 - 2003)
Average rate of change = 4115 million / 3
Average rate of change ≈ 1371.67 million per year
Therefore, the correct answer is A. $1360 million per year.