本题主要考查声音与意义的关系。

The relationship between sound and meaning is conventional because people of the same speech community have agreed to refer to the thing or the person with this cluster of sounds.

音与义之间的关系是约定俗成的，因为同一语言社区的人们都同意用这一组声音来指代事或人。

A选项“任意的”，C选项“符号的”，D选项“确定的”均不符合题干要求，故答案为B。