back 02:35:56 21 of 30 skip submit What are the x-coordinates of the O x = 0 and x = 16 2 2 critical points of f (2) =- x - 8 - ? O x=-4, x = 0, and x = 4 O x= 0, x = 8, and x = 16 O x=-4, x =0, x = 4, and x = 8