Look closely at the shape of the empty space and the feather pattern around it. The correct piece must match both the puzzle edges and the green feather design without breaking the image.

After comparing all the options, the missing piece is:

✅ 81

The other pieces may have similar colors, but their shapes or feather patterns do not fit perfectly.

🎉 If you chose 81, congratulations—you have sharp eyes, excellent observation skills, and you’re truly a smart thinker!