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

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