Brenda's teachers describe her as extremely conscientious. brenda worries about her schoolwork being complete, accurate, and neatly prepared. brenda also worries incessantly about her appearance, often stopping in the restroom to make sure that every hair is in place. when you ask brenda about her friends, she confides that she thinks that many of them don't like her. and when she's not preoccupied with academic or social matters, brenda worries about the murderers and terrorists who might be lurking around every corner.
such symptoms are most consistent with:

a. depression
b. bipolar disorder
c. a conduct disorder
d. an anxiety disorder