This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
A 27-yrs-old librarian has been worried that the small lymph nodes she can palpate in her groin are a sign of lymphoma. She also worries about developing laryngeal cancer due to the second-hand smoke she is exposed to at home. For a diagnosis of hypochondriasis, her symptoms should have been present for at least what period of time? 
Select and explain. 
A. 1 month, B. 3 month, C. 6 months, D. 1 year
C: 6 months
Answer: C: 6 months 
Explanation: Hypochondriasis is defined by DSM-IV as a persistent fear, despite medical reassurance, that one has a serious physical illness. The patient's beliefs are based on misinterpretation of benign bodily symptoms. The belief is not of delusional propoions, and the condition must persist for 6 months for this diagnosis to be made. It is estimated that from 3 to 14% of patients seen in a general medical practice may suffer from hypochondriasis.