Find the open intervals where the function is concave upward or concave downward. Find any inflection points. D Q Select the correct choice below and, if necessary, fill in the answer box(es) to complete your choice O A. The function is concave upward on the interval(s) and concave downward on the interval(s) (Type your answers in interval notation. Use a comma to separate answers as needed.) OB. 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.) OC. The function is concave upward on the The function is never interval(s) concave downward (Type your answer in interval notation. Use a comma to separate answers as needed.) OD. The function is never concave upward or downward