Answer the following questions about the function whose derivative is f' (x) = (x +4)ex. a. What are the critical points of f? b. On what open intervals is f increasing or decreasing? c. At what points, if any, does f assume local maximum and minimum values? c. Determine the local maximum/maxima, if any. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The function f has a local maximum at x = (Simplify your answer. Use a comma to separate answers as needed.) O B. There is no local maximum. Determine the local minimum/minima, if any. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The function f has a local minimum at x = ( Simplify your answer. Use a comma to separate answers as needed.) O B. There is no local minimum