Hi, Here's the sentence: They have two children, .... 1. None of whom are living with them. 2. Neither of whom are living with them. 3. All of whom are living with them. 4. Both of them are not living with them. The answer is 2. I would go for 3, because if we go with the formal rules 'neither' takes a singular verb. And 'all of whom' seems fine here except that I do not know if it must be used for more than 3 things/ peoplel, etc as does None. For example: Two of my frriends could not come this mornining. All of them were busy Thank you.