From a magazine article: Self-confidence is a dangerous virtue: it often degenerates into the vice of arrogance.
Conclusion
Self-confidence is a dangerous virtue.
Evidence
Self-confidence often degenerates into the vice of arrogance, which can be very dangerous indeed (just consider arrogantly self-confident people like Hitler and Stalin).
Evaluate
This argument is a little like saying,
Sure, that's true. There can be an excess of water drinking. But that doesn't mean we should impugn "water" as some evil substance.
However, we don't need to worry about what's wrong with this argument, since the question stem just wants us to describe it.
Goal
Find any answer that descriptively matches the argument.
The author certainly cited some examples, and the author attempted to undermine a concept "self-confidence" by warning us about the danger of its extremes "arrogance".