Ashya wants to focus on the diagnosis and treatment of psychological disorders and other problematic patterns of behavior. what area of psychology should she work in? clinical psychologycognitive psychologyorganizational psychologysocial psychology

I believe the answer is: Clinical psychology

Clinical psychology is a branch of psychology that focused on integrating science in both psychological and biological field prevent and relieving all forms of psychological disorder.
Clinical psychologists would use the combination of both psychotherapy and the usage of chemical drugs to help a patient relieve his/her disorder.