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、Taller
【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。