Помогите плезChoose the sentences which mean the same as the phrases

Помогите плез
Choose the sentences which mean the same as the phrases in the left-хэнд column.
1. It's possible that Nick doesn't go to a private school any more.
a) Nick may not attend a private school now.
b) Nick can't attend a private school now.
2. It is not possible that the boys are six. They look much older.
a) The boys mauy not be six.
b) The boys can't be six.
3. I think I'll go out, but it's very unlikely.
a) I may go out.
b) I might go out.
4. I'm almost sure that moving to a new school is a very stressful experience.
a) Moving to a new school may be very stressful.
b) Moving to a new school might be very stressful.