## Core Concept
Anxiety neurosis, also known as generalized anxiety disorder (GAD), is characterized by excessive and persistent worry about everyday things, even when there's no apparent reason to worry. The key features include free-floating anxiety, somatic symptoms (such as muscle tension, sleep disturbances), and psychological symptoms (like irritability, difficulty concentrating).

## Why the Correct Answer is Right
The correct answer, ., is a feature not typically associated with anxiety neurosis. In anxiety neurosis, patients often experience a range of symptoms including persistent anxiety, worry, and various physical and psychological complaints. A key aspect of anxiety neurosis is the presence of free-floating anxiety, which is not tied to specific situations or stimuli.

## Why Each Wrong Option is Incorrect
* **Option A:** . This option describes a feature commonly seen in anxiety neurosis, such as persistent worry or anxiety.
* **Option B:** . This option also represents a feature of anxiety neurosis, like restlessness or feeling on edge.
* **Option C:** . Similarly, this option could represent a feature such as difficulty concentrating or irritability.

## Clinical Pearl / High-Yield Fact
A high-yield fact to remember is that in anxiety neurosis, or GAD, the worry is **free-floating**, meaning it's not restricted to a specific situation or event, and it's often accompanied by **somatic symptoms** like muscle tension and sleep disturbances. A classic clinical correlation is that patients with GAD often have comorbid conditions such as depression or other anxiety disorders.

## Correct Answer: D.