The phrase "common room" in "He spends his days there writing, seeing students or taking tea with them in the drab common room" means
选项：

A:a room with toilets that is in a public place, for example in a restaurant
B:a room in a school or college where students or teachers can sit together and talk when they are not working.
C:a conferencd room
D:a classroom that can accomodate a great many students