There are 4 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 (3, 1)
Distance from target shape to orange right_triangle at (2, 3): 3
Distance from target shape to brown right_triangle at (3, 3): 2
Distance from target shape to cyan square at (2, 0): 2
Closest shape is the brown right_triangle at (3, 3) with distance 2</think>

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