Test: Summer 2021 _MAT 2160 FINAL EXAM or the formation, nd the :points on the graph at which the tangent line is horizontal. If none ext; :y= o.02x2 0.8x + 50 List all the points where the tangent line'is horizontal. Select the correct choice below and, if necessary, f G) A- The point(s) at which the tangent line is horizontal is (are)D. (Simplify your answer. Type an ordered pair. Use a comma to separate answers as needed.) 0 B. There are no points on the graph where the tangent line is horizontal. I O C. The tangent line is horizontal at all points of the graph