请通读下面对话，根据对话内容，从下面的选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。
Dad: What are you doing on the computer, Ann?
Ann: {#blank#}1{#/blank#}
Dad: Do you know them well?
Ann: {#blank#}2{#/blank#}They are my friends in real life.
Dad: Good. You know, it can be dangerous to make friends online.
Ann: Sure, Dad. {#blank#}3{#/blank#}
Dad: That's right. And you may advise your friends to be careful, too.
Ann: I will tell them later. In fact, I'll meet them this afternoon.
Dad: {#blank#}4{#/blank#}
Ann: To the city library. We'll work as volunteers there for the Internet Safety Day.
Dad: I'm so proud of you. {#blank#}5{#/blank#}
A. Have fun there!
B. It's my pleasure.
C. Don't worry, Dad.
D. Where are you going?
E. I know I need to protect myself.
F. I'm chatting with my friends online.
