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

<answer>(3, 0)</answer>