In the intake, assessment, and diagnosis domain, counselors must distinguish among common mental disorders based on symptom patterns. Generalized anxiety disorder (GAD) is characterized by:

Excessive anxiety and worry occurring more days than not

Worry that is difficult to control

Concerns that are broad and diffuse, often about everyday events or activities

Associated symptoms such as restlessness, fatigue, muscle tension, irritability, and sleep disturbance

This is captured by Option D: continual yet diffuse and overly-intense reactions to day-to-day stress.

The other options describe different clinical patterns:

A: A persistent lack of enthusiasm with fatigue is more characteristic of depressive disorders.

B: Overconcern with bodily functioning and possible ailments fits somatic symptom–related or illness anxiety presentations, not classic GAD.

C: Repetitive thoughts and ritualistic actions are typical of obsessive-compulsive disorder (OCD).

Thus, the symptom pattern most consistent with generalized anxiety disorder is D.