I don't think his family life fully explains Chris's behaviour. Chris was very upset when he found out his father was having an affair. This helps explain his animosity with father but doesn't explain his complete separation from family. Chris was supposedly close to his sister but even the few post cards he sent her eventually stop
Answer: The answer is C: By explaining the prospects Hana has to marry in the Japanese culture, it shows the narrator's compassion for Hana and the limited choices she has.
There is an envelope marked with the instructions that it is not to be opened until the death or disappearance of Dr. Jekyll. This implies that Dr. Lanyon knew something secret, but was unwilling to reveal it at first. He waited until there was no more "hope" of Dr. Jekyll staying normal.