Among the following words, “______” does NOT have derivational a

Among the following words, “______” does NOT have derivational affixes.
A、pushy
B、happier
C、upward
D、postwar
【正确答案】：B
【题目解析】：派生词缀(derivational affixes)主要是加前缀或者后缀;屈折词缀主要包括复数、第三人称单数、分词形式、比较级等形式。B项属于曲折词缀。P41。