Factitious disorder is defined as:

Factitious disorder is characterized by the intentional production or feigning of physical or psychological symptoms, most often to assume the role of a patient and gain attention or sympathy. This behavior is not motivated by external rewards, such as financial gain or avoiding legal consequences, but rather stems from a deep-seated psychological need for attention or care. Individuals with this disorder may go to great lengths, including falsifying symptoms or even causing self-injury, to maintain the sick role.

In this context, the definition aligns perfectly with the choice that describes feigning illness to gain attention. This intentionality and the lack of clear external incentives distinguish factitious disorder from other forms of illness behavior.

The other options describe different mental health or medical conditions and do not accurately reflect the nature of factitious disorder. For instance, intense fear of a specific object or situation refers to a phobia, having multiple chronic conditions pertains to the realm of chronic illnesses rather than intentional symptom fabrication, and excessive concern about health issues is aligned more closely with health anxiety or hypochondriasis. Thus, the emphasis on feigning illness for attention captures the essential features of factitious disorder.