A “boor” was merely a “peasant” and now means a “rude, ill-manne

A “boor” was merely a “peasant” and now means a “rude, ill-mannered person”, which belongs to（）of word meaning.
A、extension
B、narrowing
C、elevation
D、degradation
【正确答案】：D
【题目解析】：本题考查词义降格的应用。extension：扩大；narrowing：缩小；elevation：升格；degradation：降格。—个词的原义为褒义或中性色彩，经过语义变化，变为含有贬义的词。例如：boor原义为“农民”，现降格为“粗鲁的人”。故D选项符合题意。