Poison once meant simply "drink", but now means "poisonous drink". This is an example of（ ）of meaning.
A、extension
B、narrowing
C、pejoration
D、amelioration
【正确答案】：B
【题目解析】：本题考查poison词义变化的类型。extension：词义扩大；narrowing：词义缩小；pejoration：词义降格；amelioration：词义升格。poison以前的意思是饮料，现在的意思是毒药，可见词义的范围发生了缩小，故B选项符合题意。
