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

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