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

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