There are 6 shapes on a 9x9 grid. Which shape is closest to the green rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: green rectangle at (4, 6)
Distance from target shape to yellow rectangle at (1, 8): 5
Distance from target shape to gray right_triangle at (0, 5): 5
Distance from target shape to pink rectangle at (3, 8): 3
Distance from target shape to cyan square at (1, 3): 6
Distance from target shape to brown trapezoid at (4, 2): 4
Closest shape is the pink rectangle at (3, 8) with distance 3</think>

<answer>(3, 8)</answer>