The word picture originally denoted mere "painting", but now has come to include "drawing" and even "photograph". This example shows______of meaning. [ ]
A、extension
B、narrowing
C、degradation
D、transfer
【正确答案】：A
【题目解析】：题干中提到painting原来只是指油画，现在它也包括硬笔画和照片，这个例子是用来说明词义的扩展。