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

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