Paheli observed the shadow of a tree at 8:00 a.m., 12:00 noon and 3:00 p.m. Which of the following statements is closest to her observation about the shape and size of the shadow? (a) The shape of the shadow of the tree changes but the size remains the same. (b) The size of the shadow of the tree changes but the shape remains the same. (c) Both the size and shape of the shadow of the tree change. Neither the shape nor the size of the shadow changes.