In Monet's live broadcast, the expression "One Yen Coin Weather" was used! It means weather that cannot break down any further, just like a one yen coin cannot break down into any more fine coins. Since it cannot break down, it of course means sunny weather! On days with this one yen coin weather, it is also called "XX weather" because the predictions are correct even if you sleep with part of your body exposed.
Now here's the question!
What part of the body does "〇〇" refer to? Difficulty level is ★★☆☆☆ (2/5)!
The correct answer is "B. Belly button"!
When this weather pattern, known as "navel-topped," occurs, high pressure covers a wide area and sunny skies continue.
What an interesting metaphor! Not having to worry about changes in the weather is also great when you want to go out or do your laundry outside.
If you look at the actual pressure distribution, the center of high pressure (X) looks like your belly button!

When you check the weather section, be sure to pay attention to whether it will be a "belly up" day!
[Sources and References]
Japan Meteorological Agency "Daily Weather Map April 3, 4"
https://www.data.jma.go.jp/fcd/yoho/data/hibiten/2021/2104.pdf