Words are arbitrary symbols and independent identities so far as

Words are arbitrary symbols and independent identities so far as their （ ）are concerned.
A、spelling and meaning
B、pronunciation and use
C、spelling and pronunciation
D、meaning and collocation
【正确答案】：C
【题目解析】：词就其外部方面——拼写和发音——而言是具有任意性的符号和独立的单位。