The differences between sound and form are due to the following

The differences between sound and form are due to the following EXCEPT （ ）.
A、the fact of more phonemes than letters in English
B、stabilization of spelling by printing
C、influence of the work of scribes
D、innovations made by linguists
【正确答案】：D
【题目解析】：语言的特点D属于人为因素，非语言本身属性。