Simon has been getting mild headaches regularly since the past few months. he is convinced that the headaches are indicative of a malignant brain tumor. although magnetic resonance images provided no medical evidence in support of his claim, simon still maintains that he has a tumor in his brain and is upset about the imagined consequences. in this instance, simon is most likely to be suffering from:

The answer is Hypochondriasis.

Explanation:

Hypochondriasis or hypochondria is a condition in which a person is excessively worried about having a serious illness.

Hypochondriacs become unduly alarmed about any physical or psychological symptoms they detect, no matter how minor the symptom may be, and are convinced that they will be diagnosed with a serious illness.

To qualify for the diagnosis of hypochondria, the symptoms must have been experienced for at least six months.