Which of the following words does NOT have inflectional affixes?

Which of the following words does NOT have inflectional affixes?（ ）
A、Happier
B、Worker
C、Harder
D、Teller
【正确答案】：B
【题目解析】：B选项中的-er词缀是为了构成新单词“工人（worker）”，没有语法变化，所以不包含屈折词缀。