Final answer:
A correct diagnosis of an anxiety disorder would be supported by evidence of increased anxiety levels affecting more than one area of life over a six-month period, impacting social, occupational, or other important functions.
Step-by-step explanation:
To support a physician's diagnosis of an anxiety disorder in a client, one would look for patterns of anxiety that significantly impact functioning across various areas of life. Based on the options provided, the assessment data that would most likely support a diagnosis of an anxiety disorder is: 3) A client experiences increased levels of anxiety that affect functioning in more than one area of life over a 6-month period. This aligns with criteria set forth in diagnostic manuals such as the DSM (Diagnostic and Statistical Manual of Mental Disorders), which emphasize the duration (typically at least six months for generalized anxiety disorder) and the breadth of impact on the individual's daily life, including social, occupational, or other important areas of functioning.