Final answer:
The correct answer is C) mercy, as it was not one of Benjamin Franklin's thirteen virtues, which included sincerity, temperance, and tranquility among others.
Step-by-step explanation:
The question is asking to identify which of the listed options was not among Benjamin Franklin's thirteen virtues. Looking at his historical list, the virtues include qualities like sincerity, temperance, and tranquility. Franklin's thirteen virtues were part of his personal improvement plan and are widely studied in American history. However, mercy is not listed as one of these virtues and therefore is the correct match for the answer to the original question.