Find all the local maxima, local minima, and saddle points of the function. f ( x , y ) = x + y + 3x2 - by2 - 6 ..... Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. O A. A local maximum occurs at IN (Type an ordered pair. Use a comma to separate answers as needed.) The local maximum value(s) is/are (Type an exact answer. Use a comma to separate answers as needed.) O B. There are no local maxima. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. A. A local minimum occurs at (Type an ordered pair. Use a comma to separate answers as needed.) The local minimum value(s) is/are. (Type an exact answer. Use a comma to separate answers as needed.) O B. There are no local minima. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. A saddle point occurs at (Type an ordered pair. Use a comma to separate answers as needed.) O B. There are no saddle points