Jonathan understands that he can live without things, but he cannot live without his family.
In the excerpt, Johnathan's family is described as "five inestimable blessings". It then goes on to say "as a bonus he has had his old bicycle". When comparing these two possessions, the bicycle surviving is described as a miracle but can't be "compared to the safety of five humans heads." These details show that he values his family above everything else. The other options are wrong because he does not talk about the war in this excerpt at all. We also don't see any indication that he expected his entire family to come out of the war uninjured. In fact, he seems grateful that they were all safe.