单选题 Secretary: Good morning, Dr. Porter's office. Mr. Long: Good morning. I have an appointment with Dr. Porter at ten-thirty. I'm running a little late. ______?
【正确答案】 B
【答案解析】[注释] 从意思、语气和表达法来看，B为最佳答案，意思为“我十一点半来行吗?”。其他选项意思或语气不符合上下文的要求。