单选题 2. The Rivera Art Museum recently began charging admission. The resulting decline in visitors has been far larger than at other local museums, which have also begun charging admission. The magnitude of the decline might be due to the Rivera's location near government offices. Because an admission charge is most discouraging to those who plan a short visit, it is likely that government workers who formerly made brief visits during lunchtime and after work now do not.
Which of the following, if true, most seriously undermines the proposed explanation? ______

A、 The fee for admission to the Rivera is no larger than that charged by other museums
B、 The Rivera does not keep track of how long individual visitors stay in the museum
C、 The decline in visitors to the Rivera has been no greater in workdays than it has been on nonworking days
D、 The museum with the smallest decline in visitors is the most popular with visitors from other countries
E、 In the period between the announcement that there would be an admissions charge and its actual introduction, there was an increase in visitors at the Rivera.

【正确答案】 C

【答案解析】 C：该选项说明，非工作日也会发生不少于工作日的游客数量降低，证明除了靠近政府办公室以外，还有其他原因也会导致游客数量发生变化，属于“直接削弱原因”，正确。
A：该选项说明游客数量下降并不是由价格高导致的，反而进一步提升了是因为靠近政府办公室而导致游客数量下降的可能性，故不选。
B：里维拉是否记录游客的参观时间长短，并不会影响导致游客数量下降的原因，与原文无关，故不选。
D：从文中看不出国外游客对博物馆的游客数量贡献的大小，与原文无关，故不选。
E：文章讨论的是为什么收费以后游客数量减少，和收费之前游客数量短暂上升无关，故不选。