When do you use comas and give an example

Which of the following was an economic event that led to an expansion of voting rights in the us? a) the panic of 1819 b) the war of 1812 c) the campaign of 1828 d) the “corrupt bargain” of 1824

The story behind the story is a a human interest article b concerned with the feelings of people involved in a headline event ca kind of special feature d all of these e none of these

Brutus: but as he was ambitious, i slew him. . who is here so base that would be a bondman? if any, speak, for him have i offended. who is here so rude that would not be a roman? if any, speak, for him have i offended. who is here so vile that will not love his country? if any, speak, for him have i offended. i pause for a reply. which rhetorical device does brutus use in this excerpt?