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

<answer>(0, 1)</answer>