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

<answer>(2, 3)</answer>