Today is Sunday. There's no school. It is sunny. Charlie and his father are going to the park. Look. Charlie is riding his bike. He is very happy. His father is sitting under a big tree. He is reading a newspaper. In the afternoon, the weather is bad. It is cloudy. Now it is raining. Charlie and his father have no umbrella. They are running home. But they forget their bike.

在一个不透明的纸箱中放入m个除颜色外其他都完全相同的球，这些球中有4个红球，每次将球摇匀后任意摸出一个球，记下颜色再放回纸箱中，通过大量的重复摸球实验后发现摸到红球的频率稳定在$\frac{1}{5}$，因此可以估算出m的值大约是（　　）

A. B. C. D. E.