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 (2, 1)
Distance from target shape to pink right_triangle at (1, 3): 3
Distance from target shape to brown square at (0, 0): 3
Distance from target shape to red trapezoid at (1, 2): 2
Closest shape is the red trapezoid at (1, 2) with distance 2</think>

<answer>(1, 2)</answer>