There are 3 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 (2, 3)
Distance from target shape to pink rectangle at (5, 0): 6
Distance from target shape to cyan right_triangle at (4, 0): 5
Closest shape is the cyan right_triangle at (4, 0) with distance 5</think>

<answer>(4, 0)</answer>