Which of these defines social search?

Question: Which of these defines social search?

Multiple Choice Options:

A.) Asking a search engine a question that is answered by a real person on the other side.

B.) Modifying search results based on popularity of a Web page.

C.) Modifying search results based on a ranking of a Web page.

And here is the definition for others just in case.

Social search is a behavior of retrieving and searching on a social searching engine that mainly searches user-generated content.

A social search engine is an enhanced version of a search engine that combines traditional algorithm - driven technology with online community filtering to produce highly personalized results.