How would you describe a person that exhibits obsessive behavior?

A person exhibiting obsessive behavior is best described as excessively focused and preoccupied. This description captures the essence of obsessive behavior, which often involves intense and persistent thoughts or urges that dominate a person's focus. Individuals might find themselves unable to divert their attention from specific ideas or tasks, often leading to compulsive actions meant to alleviate their distress or anxiety.

The other choices do not align with the characteristics of obsessive behavior. Being much too relaxed, disinterested, or completely laid-back suggests a lack of concern or engagement, which is not characteristic of someone who is obsessive. Instead, obsessive individuals are typically driven by a heightened sense of urgency or anxiety related to their thoughts or compulsions. Therefore, the option emphasizing excessive focus and preoccupation is the most accurate description of obsessive behavior.