问题

“May I speak to your manager Mr Williams at five o’clocktonight”— “I’m sorry Mr Williams ________ to a conference by then”
A:Not the teacher but the students
B:Both the students and the teacher
C:Neither the teacher not the students
D:Not the students but the teacher
B:Both the students and the teacher
C:Neither the teacher not the students
D:Not the students but the teacher
正确答案是: