A. Why did Mary have to go to a new school? 1) her sister got a new job 2) she didn't like her previous school 3) she moved to a new place.

Для ответа на вопрос нужно обратиться к тексту. В начале текста говорится: "Her family moved to a new city, so she had to go to a new school..."

3) she moved to a new place.

Ответ: 3