The case of nadean cool, who was purported to have more than a hundred different personalities, is an example of the critical thinking concept of

The correct answer is extraordinary claims.

Extraordinary claims refer to claims that are directly contradictory to evidence and existing empirical data. Extraordinary claims are basically claims that are very likely to be untrue. Examples of extraordinary claims can include: ghosts haunting your basement, believing that wishful thinking alone can get you your dream car, and claiming that alcohol abuse does not affect health.