What does the author mean by “unsweetened reading” in Paragraph

What does the author mean by “unsweetened reading” in Paragraph 3?
A、Online reading.
B、Difficult reading materials.
C、Regular books.
D、Serious and sad stories.
【正确答案】:C
【题目解析】:细节推断题。定位于第三段的By offering children candy—coated books, multimedia is guaranteed to sour them on unsweetened reading.意思是“通过向孩子提供糖衣包装的读物,多媒体使孩子们对无聊的书面阅读变得更加不感兴趣。”“无聊的书面阅读”就是指“通常的读物”,C选项是正确的。unsweetened reading不是Online reading A选项不对;也不是指Difficult reading materials;更不是D选项所指的内容。