There are 4 shapes on a 5x5 grid. Which shape is closest to the green right_triangle 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 right_triangle at (1, 4)
Distance from target shape to pink square at (0, 0): 5
Distance from target shape to gray square at (2, 4): 1
Distance from target shape to red rectangle at (0, 3): 2
Closest shape is the gray square at (2, 4) with distance 1</think>

<answer>(2, 4)</answer>