Final answer:
The virtue that was not listed among Benjamin Franklin's thirteen virtues is 'mercy'. Franklin's virtues focused on personal ethics and behavior but did not include mercy explicitly.
Step-by-step explanation:
The question you have asked pertains to Benjamin Franklin's thirteen virtues, which were a set of moral guides he created for personal improvement. The virtue that was not one of Franklin's thirteen virtues is mercy (option C).
Franklin's list did include virtues like sincerity, temperance, and tranquility, but mercy was not one of them. His list was meant to cover various aspects of personal ethics and behavior, such as speaking the truth (sincerity), moderation in all things (temperance), and calmness (tranquility).