Alexis Has Been Diagnosed with a Learning Disability

Multiple Choice

Alexis has been diagnosed with a learning disability.She doesn't believe that the psychologist was accurate in this diagnosis,so she decided to seek out additional information about the disability,and its rate of misdiagnosis.She finds several websites and a couple of books that suggest that the diagnosis for the particular disability is wrong 20 percent of the time.Alexis is confident that hers is a case of misdiagnosis,and even after getting three additional evaluations from other diagnosticians (who all agree with the original diagnosis) ,Alexis refuses to believe otherwise.What does this example illustrate

A)  availability heuristics 
B)  gambler's fallacy 
C)  overestimating the improbable 
D)  confirmation bias leading to belief perseverance