For y = e "4X - 4x determine concavity and the x-values where points of inflection occur. Do not sketch the graph. On which interval(s) is the function concave down? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. CA. The function is concave down on (0,co) (Type your answer in interval notation. Use a comma to separate answers as needed.) O B. There are no intervals on which the curve is concave down. On which interval(s) is the function concave up? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The function is concave up on (Type your answer in interval notation. Use a comma to separate answers as needed.) O B. There are no intervals on which the curve is concave up