【单选题】

The author offers all of the following ideas as proof that there is no direct correspondence between words and thingsEXCEPT

A、Language has other functions than that of reference.
B、Once a word is grouped into a class, no one-to-one correspondence exists between it and what it signifies.
C、Many words refer to objects that do not exist in the worlD、
D、Function words do not refer to objects.
E、Proper nouns usually refer to unique entities.