根据对话内容，从所给的七个选项中选出可以填入空白处的最佳选项，使对话内容完整。

Jack: Tom, be careful! You almost felt down. 

Tom: Yes, I'm OK. Don't worry.

Jack: You'd better not look at your phone while walking.

Tom: OK, I won't.

Jack: 

Tom: You saw my pictures on my WeChat, didn't you?

Jack: Yes. 

Tom: Just a little traffic accident. 

Jack: 

Tom: There was nothing serious, because we all wore the seat belts. 

Jack: OK. We should know how to protect ourselves. 

Tom: By the way, have you got vaccinated（接种疫苗）against COVID-19?

Jack:  Many people have got vaccinated in our city. 

A. Yes, I have. 

B. Are you all right?

C. Did you see a dentist?

D. I'm sorry to hear that.

E. What happened?

F. Will you go with your friends?

G. It seemed that you weren't happy on the WeChat yesterday.