Which word describes someone who is overly preoccupied?

The term "obsessive" accurately describes someone who is excessively preoccupied with a particular thought, idea, or activity. This word conveys a sense of intensity and fixation that transcends normal levels of interest or concern. People characterized as obsessive often find it difficult to shift their focus away from the subject of their preoccupation, leading to behaviors that may be compulsive or intrusive. This context provides a clear understanding of why "obsessive" is the most fitting choice for someone who is overly preoccupied.

In contrast, the other options depict a lack of intensity or concern. For example, "relaxed" and "laid-back" suggest a calm and easy-going demeanor, devoid of any excessive focus or worry. "Indifferent," on the other hand, implies a lack of interest or care altogether. These terms do not convey the same level of intensity or fixation that "obsessive" presents, making them unsuitable choices for describing someone who is overly preoccupied.