The 2010 census in a particular area gives us an age distribution that is approximately given (in millions) by the function f(x) =40.4 + 2.16x - 0.837x2 where x varies from 0 to 9 decades. The population of a given age group can be found by integrating this function over the interval for that age group. (a) Find the integral over the interval [0,9]. (Round to the nearest integer as needed.) What does this integral represent? A. About 248 million people aged 0 to 90 have ever lived in this area from year 0 through 2010. O B. The number of people in this area increased by about 248 million people aged 0 to 90 in 2010. O C. The total number of people in this area under 9 years old was about 248 in 2010. O D. The total number of people in this area aged 0 to 90 was about 248 million in 2010. (b) Find the number of people alive in 2010 that were born in the eighties, that is, those in the range of 1 to 2 decades in 2010. million (Round to the nearest integer as needed.)