Concept:The sentence describes an unhealthy or excessive involvement with an activity.
Explanation:The phrase "something to worry about" signals a negative or harmful habit.
"Devotion" and "commitment" suggest positive dedication, not a problem.
"Attachment" means a general emotional bond, but not necessarily harmful.
"Addiction" means a strong dependence on an activity that is hard to control.
This fits the worry expressed in the sentence.
Therefore, the correct completion is with "addiction".
Answer:D. addiction