If the question asks how an author show a character as an ironic figure, is that asking you about literary devices or character analysis?about A...

If your essay response is going to focus on a character,
then you are doing a character analysis.  There may be literary devices that contribute
to characterization through.  For example, if the character is supposed to be poor and
uneducated and an author uses a local color dialect to bring that characterization
across, then that is a literary device.  The important thing to remember is to analyze
HOW the device contributes to the CHARACTERIZATION. 

If the
character you are analyzing is considered ironic, you must determine what exactly that
means.  Are his/her actions different from what was expected of him/her? (Situational
irony).  Are the character's comments ironic? (Verbal irony) Does the character provide
information that then provides the audience with knowledge that other characters don't
have? (dramatic irony).  In the course of analyzing these forms of irony, it would be
logical to discuss diction, foreshadowing, use of dialogue, symbolism, etc. which fall
under a typical list of literary devices.  Ask yourself how these techniques are
contributing to the irony of the character. 

The links
below will give you some more suggestions on how to write these kinds of
responses.