How Do You Cite Two Papers Published in the Same

Multiple Choice

How do you cite two papers published in the same year by exactly the same authors?

A) Place a 1 or a 2 after the date of each reference
B) Use the title of the article instead of author and date in your citation
C) Put one of the references in quotes and the other not in quotes to distinguish them
D) Place a lowercase a or b after the date of each reference