There are 5 shapes on a 4x4 grid. Which shape is closest to the green square 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 square at (3, 2)
Distance from target shape to gray rectangle at (1, 2): 2
Distance from target shape to red rectangle at (2, 1): 2
Distance from target shape to blue square at (1, 3): 3
Distance from target shape to pink square at (0, 0): 5
Closest shape is the gray rectangle at (1, 2) with distance 2</think>

<answer>(1, 2)</answer>