Help! I'm confused

Find the open intervals where the function is concave upward or concave downward. Find any inflection points. Select the correct choice below and fill in any answer boxes within your choice. A. The function is concave up on and concave down on (Type your answers in interval notation. Use a comma to separate answers as needed.) B. The function is concave down on ( - co,00). O C. The function is concave up on ( - 00,00). Select the correct choice below and fill in any answer boxes within your choice. O A. The function has an inflection point at (Type an ordered pair. Use a comma to separate answers as needed.) O B. The function does not have an inflection point. X (3, - 39)