Locate the critical points of the following function. Then use the Second Derivative Test to determine whether they correspond to local maxima, local minima, or neither. f(x) = - 2x-6x2 +9 What is(are) the critical point(s) of f? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The critical point(s) is(are) x= (Use a comma to separate answers as needed. Type an integer or a simplified fraction.) O B. There are no critical points for f. What is/are the local maximum/maxima of f? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The local maximum/maxima of f is/are at x= (Use a comma to separate answers as needed. Type an integer or a simplified fraction.) O B. There is no local maximum of f. What is/are the local minimum/minima of f? Select the correct choice below and, if necessary, fill in the answer box to complete your choice.