Answer:
D. The poor suffer the most in war.
Step-by-step explanation:
The poor mother, even though her own son is in the war, took in four enemy soldiers and cared for them like they were her own sons.
"they are poor and because every new burden crushes them down"
"who suffer most cruelly the atrocious miseries of war because they are the feeblest and offer least resistance"
These lines from the passage is proof that the poor have no side in wars, for according to the narrator, "patriotic hatred [...] belongs to the upper class alone". Either way, no matter who wins, it is the poor who will suffer the most in any circumstance.