The trend for bigger housing thus poses ethical questions. Should Americans accept a system in which the middle and upper classes enjoy a luxurious lifestyle, using the low-wage labor of others? Are we willing to accept a system in which an increase in amenities purchased by the affluent means a reduction in amenities for the poor. What questions arise from living big?A. Questions related to moral principles.B. Questions having to do with labor cost.C. Questions about what lifestyle to promote.D. Questions concerning housing development.

本题考查对段落核心主旨的理解，需结合上下文判断问题类型。段落通过描述“居住大房”引发的伦理问题，指出中上阶层依赖低薪劳工维持奢华生活，以及富人增加便利设施导致穷人资源减少的现象。关键点在于“ethical questions”（伦理问题），需明确选项中哪一项最贴合道德层面的讨论。

选项分析

A) Questions related to moral principles

• 段落明确提到“ethical questions”，并指出中上阶层依赖低薪劳工、富人资源增加导致穷人资源减少的现象，均属于道德判断范畴。
• 正确选项。

B) Questions having to do with labor cost

• 虽然提到“low-wage labor”，但段落核心是道德问题（如阶级剥削），而非单纯讨论劳动成本。
• 排除。

C) Questions about what lifestyle to promote

• 段落虽涉及“luxurious lifestyle”，但问题本质是道德争议（如社会公平），而非讨论生活方式的选择。
• 排除。

D) Questions concerning housing development

• 段落未提及住房建设本身，而是聚焦于住房引发的道德矛盾。
• 排除。