B. What did Mary do near the river?

The text says: "Mary lived in the country. Her family had a farm. There was a river near the farm. Mary liked to go to the river in the afternoon after school when the weather was nice. She walked along the river. Some boys fished there. Some girls read books near the river." From this, we can infer that Mary often walked by the river, and sometimes girls read books near the river. The question asks what Mary did. While she walked, the text also mentions "Some girls read books near the river." Given the options, and the fact that Mary enjoyed reading books, it's likely that she also read books near the river.

Ответ: ② She read books.