There are 4 shapes on a 6x6 grid. Which shape is closest to the blue 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: blue rectangle at (3, 2)
Distance from target shape to pink trapezoid at (1, 4): 4
Distance from target shape to green right_triangle at (4, 0): 3
Distance from target shape to purple trapezoid at (2, 4): 3
Closest shape is the green right_triangle at (4, 0) with distance 3</think>

<answer>(4, 0)</answer>