Answer:
The boy with the black silk handkerchief on his face has no medals because He had not been in the service long enough before his injury.
Step-by-step explanation:
The question is not complete, here is the complete question:
In Ernest Hemingway's “in another country,” Why does the boy with the black silk handkerchief on his face have no medals? 
A He had not been in the service long enough before his injury. 
B He has only just enlisted and is getting ready to go into battle. 
C The boy has refused the medal because he feels he hasn't earned it. 
D No medals are given to soldiers who are below the age of twenty.
 It was required during war to be on service a specific amount of hours in order to be worthy of a medal, This boy had a black silk handkerchief on his face because of an injury he had suffered within the first hour he had been in the front line, this eliminated his chances of getting a medal even though he had lost his nose in battle.