options: f : so helen went to san francisco on vacation to meet a friend . f : helen ! could you tell me why do you want to tour a university ? f : you mean bob went to san francisco to visit his sister . f : how do you feel after visiting your sister in san francisco ?
article: f : where did you go on vacation ? m : i went to san francisco , it 's a really pretty city . f : why san francisco ? m : oh my sister works there . i stayed with her . she loves shopping , so we went shopping every day . look , i got this sweater .