A person believes he is sutfering from an illness in spite of all the investigations being negative. Diagnosis is

(B) Hypochondriasis# Hypochondriasis is a persistent preoccupation with fear or belief of having disease, based on persons own interpretation of normal body function or minor physical abnormality.> This preoccupation persists despite repeated reassurance based on appropriate clinical examination & thorough investigation> The patient in question is persistently preoccupied about her disease (headache) despite of all normal investigations and seeks another consultation as she still insists that there is something wrong in her head.