When given the choice between the line of men and the line of children, Salva chooses the men’s line even though he is only 11 years old. What does that say about Salva?

Salva's choice speaks to his maturity.... he sees himself as a man, something his accomplishment attests to.

This says about Salva that he acts like a man .on page 11 Salva remembers his father telling him to act like a man which is probably why he was in the men's line