What background knowledge would best support this inference about mario

People often talk about interesting things that they have seen

People often talk about interesting things that they have seen  

Explanation:   I read the passage and did the quiz:)

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.