Why is "through the tunnel" a coming-of-age story? because jerry goes through a rite of passage in "through the tunnel," the story is classified as coming-of-age story. in "through the tunnel," swimming through the tunnel is important to jerry because he wants to impress the older boys. in "through the tunnel," jerry does not challenge himself. in "through the tunnel," jerry does not feel as emotionally close to his mother as he does to his father.

Just based on the options I would say it's a coming of age story because he goes through a rite of passage. I don't think it would be because he does not feel as close to his mother or that Jerry does not challenge himself. It could possibly be because he wants to impress the older boys but i think the first option is more likely as in real life people do go through rites of passages as they come of age. 

Inun ask someone