Consider the graph to the right. Explain the idea of a critical value. Then determine which x-values are y critical values, and state why. Which xvalues are critical values? O A. All x-values are critical values because they all occur at relative extrema or where the slopes of the tangent lines do not exist. 0 B. x and x because a comer exists at these x-values. 4 7 O C. x1, x3, x4, x5, x6, x7, x3, and x10 because the slopes of the tangent lines at these points are 0 or do not occur. 0 D. x1,x3, x5, x6, x8, and x10 because relative extrema occur at these points. v