There are 5 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 (3, 1)
Distance from target shape to cyan trapezoid at (4, 0): 2
Distance from target shape to gray square at (3, 2): 1
Distance from target shape to yellow rectangle at (3, 4): 3
Distance from target shape to pink square at (2, 0): 2
Closest shape is the gray square at (3, 2) with distance 1</think>

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