参考答案

正确答案：C
解析：根据题干关键词an invention or some innovation in commerce定位到第二段第三句：We are again entering a period of social change as Americans are recalibrating our sense of what it means to be a citizen, not just through voting or volunteering but also through commerce: by what we buy. 可知，美国进入一段社会变革时期。美国人正在重新调整做一名市民的意义。这个调整并不只是通过投票或做一名自愿者进行的，同时也是通过自己所购买的东西进行的，故选C)项。C项中的consuming是原文的by what we buy的同义转述。