In the book, To Kill a Mockingbird, who would be the best friend and give three reasons explaining why?

I think you could argue that Boo is the "best friend" in
this story. He is always there, no matter what. He leaves gifts to the children as his
show of friendship, takes care of Jem when he loses his pants, and, ultimately, saves
their lives in the end. To me, a best friend is someone who is always there for you, who
"watches your back" and is willing to risk of himself or herself in order to help you
out. Boo does this when he emerges from the shadows to save Scout and Jem. Up until this
point, he has stayed in the darkness because he is more comfortable there. Scout
realizes this, and this is why she takes him out of the light of the house and onto the
porch where the light is dimmer. This is also why she takes his hand and walks him home.
In true best friend fashion, she returns the favor that he has done by saving her life
in the best way that she can. He has protected her and Jem, now she will protect him on
the walk home. This is what a best friend does. They give of themselves unselfishly,
never asking for anything in return, never expecting anything in
return.