Both boys were moved from their beloved home:Bruno from his home in berlin when his father got a new position in Nazi regime as commandment of auchwitz, Shmuel from his home in poland when he was taken as a prisoner of war and put in a concentration camp.
Bruno lives wealthy and luxurious with maids and servants and shmuel lives in an overrun filthy barrak overseen by cruel and vicious gaurds
The correct option is D. Ration refers to a fixed amount of a particular commodity which is officially allowed during a time of shortage such as the one experience during war time. A similar word that can be used instead of ration is portion.