There are 4 shapes on a 5x5 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 (1, 3)
Distance from target shape to yellow square at (2, 3): 1
Distance from target shape to orange right_triangle at (1, 0): 3
Distance from target shape to pink square at (2, 0): 4
Closest shape is the yellow square at (2, 3) with distance 1</think>

<answer>(2, 3)</answer>