**Core Concept**
Somatoform disorders are a group of psychiatric conditions characterized by physical symptoms that cannot be fully explained by a medical condition, substance, or another mental disorder. They are often associated with psychological distress and impairment in social, occupational, or other areas of functioning.

**Why the Correct Answer is Right**
The correct answer is not a direct somatoform disorder because it does not fit the diagnostic criteria for somatoform disorders as outlined in the DSM-5. Somatoform disorders typically involve one or more physical complaints that are not fully explained by a medical condition, such as chronic pain, fatigue, or gastrointestinal symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Hypochondriasis is a type of somatoform disorder characterized by excessive worry about having a serious illness despite medical reassurance.
**Option B:** Conversion disorder is a type of somatoform disorder characterized by symptoms affecting voluntary motor or sensory function, such as paralysis or numbness.
**Option C:** Factitious disorder is a type of somatoform disorder characterized by intentionally producing or feigning physical or psychological symptoms in order to assume the sick role.

**Clinical Pearl / High-Yield Fact**
Somatoform disorders should be distinguished from malingering, where an individual intentionally produces or feigns symptoms for external incentives such as financial gain.

**Correct Answer:** D.