Here are the correct options to complete the dialogue:
Mrs Jones: Hello, Ryan! How are you? How are your mother and your brother, Alex?
Ryan: Hi, Mrs Jones. We're all very well. Mum's really happy! She’s going to get married on Saturday!
Mrs Jones: That's wonderful! So, who is she going to marry?
Ryan: A really nice man called David. I like him.
Mrs Jones: So, your life is going to change?
Ryan: Yes, it is!
Mrs Jones: Are you going to move house?
Ryan: Yes, we are. After the wedding, Mum and David are going to go on holiday for a week. Alex and I are going to stay with our grandparents. Then we are going to move to a bigger house. It's got three bedrooms. I’m not going to share a bedroom with Alex anymore!
So the choices are:
1 - b) is she going to marry?
2 - c) is going to change
3 - c) Are you going to move
4 - a) are going to go
5 - b) are going to stay
6 - b) are going to move
7 - c) I'm not going to share