C. 歯痛(はいた)みを音楽(おんがく)で和(やわ)らげてもらうため。

The next night, just as Goshu was about to begin practice, this time a badger visited. The badger was suffering from a terrible toothache and pleaded with Goshu, "Please soothe this pain with music." Goshu, though perplexed, tried to respond to the badger's earnest wish and played a gentle melody. Strangely, as Goshu played with all his heart, the badger's toothache gradually subsided, and eventually, it fell asleep. This incident became a valuable experience for Goshu, teaching him that music is not merely a display of skill, but possesses the power to resonate with others' hearts and bring healing.