阅读下列短文，从短文后各题所给的A、B、C和D四个选项中，选出可以填入空白处的最佳选项。

A 24-year-old boy looking out from the train's window shouted. "Dad, look, the trees are going behind!" And Dad1.

A young couple sitting nearby looked at the 24-year-old's childish behavior with pity. Suddenly he2 

shouted, "Dad, look, the clouds are running with us!"

The couple couldn't resist and said to the old man,"3don't you take your son to a good doctor?" The old man smiled and said, "I did and we are just coming back from the4. My son was blind from birth. He just got his eyes today."

Every single person on the planet has a story. Don't judge people before you truly know them. The truth might5you.