Find the open intervals where the function is concave upward or concave downward. Find any inflection points. AY 26 X AL Select the correct choice below and, if necessary, fill in the answer box(es) to complete your choice. OA. The function is concave upward on the interval(s) on the interval(s) (Type your answers in interval notation. Use a comma to separate answers as needed.) OB. The function is concave upward on the interval(s) concave downward. (Type your answer in interval notation. Use a comma to separate answers as needed.) and concave downward The function is never OC. The function is concave downward on the interval(s). The function is never concave upward. (Type your answer in interval notation. Use a comma to separate answers as needed.) OD. The function is never concave upward or downward. OA. The function has an inflection point at Select the correct choice below and, if necessary, fill in the answer box to complete your choice. OB. The function does not have an inflection point. (Type an ordered pair. Use a comma to separate answers as needed.)