This is the Unit 6 lesson 5 quiz does anyone have the answers for this question specifically?

What effect does the author’s use of flashback have on the reader of “Cranes”? (1 point)
It explains why Tok-chae feels he must escape from Song-sam.
It explains why Song-sam feels such powerful rage at Tok-chae.
It explains why Song-sam decides to let Tok-chae free in the way he does.
It explains why Song-sam is jealous that Tok-chae married Shorty.