There are 6 shapes on a 4x4 grid. Which shape is closest to the pink right_triangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: pink right_triangle at (0, 3)
Distance from target shape to cyan trapezoid at (3, 2): 4
Distance from target shape to orange square at (3, 1): 5
Distance from target shape to red square at (2, 0): 5
Distance from target shape to green right_triangle at (2, 3): 2
Distance from target shape to gray rectangle at (2, 2): 3
Closest shape is the green right_triangle at (2, 3) with distance 2</think>

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