口头表达：评价人物的贡献与影响 — 英语填空题

在口头介绍中，介绍者要评价科学家 Maya Chen 的贡献与影响。已知她设计了价格低廉的净水设备，帮助偏远社区获得安全饮用水。选择最恰当的一句填入空格。 A. She has worked as a scientist for many years. B. She is thoughtful and enjoys solving problems. C. Her affordable water filters have helped remote communities gain access to safe drinking water. 答案：___