To better understand the events of the excerpt, the most useful information would be:
d. Knowing whether it was common in this culture for mothers to choose wives for their sons.
This information would clarify the motivations and actions of Chen's mother in seeking a match for her son with Miss Wang, as well as the societal norms surrounding marriage and betrothal during that time. Understanding the role of mothers in matchmaking would provide context to the relationships and intentions expressed in the excerpt.