Hi A,
Actually there is conditional reasoning in this stimulus. But answer choice (A) is not a Mistaken Negation--it's the contrapositive!
Let's walk through it:
First, the author tells us that an being willing to tell funny stories about yourself means you are self-confident. Diagram that something like this:
WTFS
SC
Next, the author tells us that WTFS is even more revealing than being willing to have others tell funny stories about you with regard to your level of self-confidence. This is a little bit tricky because the phrasing is subtle, but the author has basically told us that being willing to hear funny stories also indicates that you are self-confident. You can diagram that like this:
WTHS
SC
Those two statements can be combined as:
WTFS or WHFS
SC
The contrapositive would then be:
NOT SC
NOT WTFS and NOT WHFS
That's what answer choice (A) says. If a person is not self-confident, then they are not willing to tell or hear funny stories about himself or herself.
Hope this helps!
Best,
Kelsey