There are 5 shapes on a 6x6 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 (3, 4)
Distance from target shape to purple rectangle at (5, 3): 3
Distance from target shape to gray trapezoid at (0, 3): 4
Distance from target shape to cyan right_triangle at (1, 3): 3
Distance from target shape to pink rectangle at (4, 4): 1
Closest shape is the pink rectangle at (4, 4) with distance 1</think>

<answer>(4, 4)</answer>