Answer :
The sentence which correctly uses dashes for punctuation is :
C) I would ask—or insist—that he brings his wife to the meeting.
The punctuation that is to be used in this sentence is a comma. The comma is a punctuation mark that is used for separating different parts of a sentence, separating parenthesis, separating different elements in a series and distinguishing dialogues and quotations. In this sentence, the commas are used to separate the parenthetical element.