A client reports excessive worry, restlessness, and muscle tension.

Choice A reason: Panic refers to an acute, intense, and overwhelming surge of fear often accompanied by physical symptoms like palpitations, shortness of breath, and a sense of impending doom. While it involves worry, it is characterized by its sudden onset and extreme physiological intensity rather than the sustained, generalized worry and muscle tension described. Choice B reason: Anxiety, specifically Generalized Anxiety Disorder, is clinically characterized by excessive, uncontrollable apprehension regarding various events or activities. It manifest through somatic symptoms such as restlessness, fatigue, difficulty concentrating, and significant muscle tension. It represents a persistent state of hyperarousal and cognitive dread that interferes with daily functioning and psychological well-being. Choice C reason: Rumination involves repetitive, circular, and passive thinking focused on causes and consequences of one's distress or past failures. While it occurs in anxious states, it is primarily a cognitive process associated with depression. It does not inherently encompass the physiological symptoms of restlessness and muscle tension that define clinical anxiety. Choice D reason: Paranoia is a pattern of pervasive distrust and suspiciousness of others, where motives are interpreted as malevolent. While paranoia can generate significant stress, its core feature is the thematic content of persecution or conspiracy rather than the generalized "excessive worry" and physical restlessness typically seen in anxiety spectrum disorders.