There are 6 shapes on a 4x4 grid. Which shape is closest to the red rectangle 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 rectangle at (3, 0)
Distance from target shape to blue rectangle at (1, 0): 2
Distance from target shape to green rectangle at (1, 1): 3
Distance from target shape to cyan right_triangle at (3, 2): 2
Distance from target shape to brown trapezoid at (0, 3): 6
Distance from target shape to gray rectangle at (3, 3): 3
Closest shape is the blue rectangle at (1, 0) with distance 2</think>

<answer>(1, 0)</answer>