There are 6 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 (2, 3)
Distance from target shape to brown right_triangle at (1, 1): 3
Distance from target shape to cyan right_triangle at (1, 3): 1
Distance from target shape to red rectangle at (0, 1): 4
Distance from target shape to blue rectangle at (0, 3): 2
Distance from target shape to orange rectangle at (3, 1): 3
Closest shape is the cyan right_triangle at (1, 3) with distance 1</think>

<answer>(1, 3)</answer>