In paragraph 14 of " The Boy Who Dreamed Too Much, what does the metaphor “building imaginary castles in the sky” suggest about Fritz?

b. He knows he has improved and is continuing to improve.

Explanation:

Coates openly claims that he has gotten much better in French. He doesn't actually remember since when but he knows that he has improved a lot in French.

He admits that there were times when he wanted to give up because of fatigue and hopelessness but times like in Montreal really encouraged him to keep improving.

Coates says that learning French is like taking a canoe from California to China. It is not an easy task and there's so much room to learn and improve. Thus, he hopes that he would keep on improving every single day.