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

<answer>(1, 0)</answer>