The question is testing knowledge of verb tenses to describe an interrupted action in the past. - The correct answer is C. Past Continuous, which is used to describe an action that was ongoing when it was interrupted. - Option A, Past Simple, is used for completed actions in the past, not necessarily interrupted ones. - Option B, Present Perfect, is used for actions that have a connection to the present, not for past interrupted actions. - Option D, Future Tense, is used for actions that will happen in the future, not for past actions.