The two most common ways dystopias are created in stories are: When a new government tries to solve a problem/ forms or gives power to a corporation, technology, or belief. And when an Apocalyptic event occurs.
A literary device is any specific aspect of literature, or a particular work, which we can recognize, identify, interpret and/or analyze. Both literary elements and literary techniques can rightly be called literary devices.
This is an easy one, use the order of elimination for problems like these in the future, but the answer is (A).