Which figure of speech is used in the idiom sum and substance?（

Which figure of speech is used in the idiom sum and substance?（ ）
A、​Euphemism
B、Personification
C、Alliteration
D、Synecdoche
【正确答案】：C
【题目解析】：本题考查习语使用的修辞手法。 Euphemism：委婉语；Personification：拟人；Alliteration：头韵；Synecdoche：借代。sum and substance：要点。使用了头韵的修辞手法。故C选项符合题意。