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

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