Answer:
C
Explanation:
This shows what Piggy thinks of the people walking up the mountain, not simply his immediate reaction. (I've never read the book but I'm assuming this was said by Piggy)
The main idea of this excerpt is the fact that the Grimm Brothers had a strong belief (that the most natural and pure forms of culture were linguistic and based in history) and in following it, they <em>saved</em> the fairy tale. In order to do so, the author gives a supporting detail and reveals the main idea, followed by more details.
The appositive is usually a group of words related to a noun, usually a subject, and describes it in more detail.
The appositive here is a river that flows through Egypt.
Another way of easily spotting an appositive is by looking for commas - if it is separated from the rest of the sentence by commas, it is likely to be an appositive.
