Which of the following represents a symptom of hyperactivity/impulsivity associated with ADHD?

The symptom "often 'on the go'" accurately reflects a hallmark trait of hyperactivity/impulsivity in individuals with ADHD. This behavior is characterized by a constant need for movement, excessive fidgeting, or an inability to remain still. Children or adults with ADHD may seem restless and may have difficulty staying seated in situations where it is expected, leading to a tendency to be in constant motion.

In contrast, the other symptoms mentioned are more closely associated with inattention rather than hyperactivity or impulsivity. Difficulty organizing tasks and losing things are reflective of challenges in maintaining focus, which is not the same as the hyperactive component. Though it is common for individuals with ADHD to exhibit a mixture of symptoms related to both inattention and hyperactivity/impulsivity, in this specific context, being "on the go" directly represents hyperactivity/impulsivity.