This question assesses the understanding of past perfect tense. The past perfect tense (had + past participle) is used to show that an action happened before another action in the past. Option A uses the simple past incorrectly. Option B uses present perfect which isn't suitable to show a time relation in past. Option D is about future tense. * **Core Concept:** Past Perfect Tense * **Solution:** Option C uses past perfect tense correctly indicating eating dinner happened before watching the movie, both in the past. Option A, B, and D use incorrect tenses. * **Detailed Analysis:** * **A:** Incorrect use of the simple past tense. Should be 'finished' with 'have/has'. * **B:** Incorrect use of present perfect which cannot demonstrate that one action happened before another in the past. * **C:** Correctly uses the past perfect ('had eaten') to indicate an action completed before another past action ('movie started'). * **D:** Incorrect, because it refers to future tense. * **Common Mistake:** Confusing the past perfect tense with the simple past or present perfect.