He . . . . . . . . for you all day. He's still waiting now.

Answer: Option C

Definition:
The sentence describes an action that started in the past and is still continuing in the present. This situation requires the use of the present perfect continuous tense, which is formed using "has/have been + verb-ing". Correct Answer:
The correct option is Option C: has been waiting. Explanation:
- The phrase "He's still waiting now" indicates that the action is ongoing.
- The present perfect continuous tense is used for actions that started in the past and are still happening in the present.
- The correct structure is: Subject + has been + verb-ing.
- Therefore, the correct sentence is: He has been waiting for you all day. He's still waiting now.
Why Other Options Are Incorrect:
- Option A: waited → Incorrect because "waited" is in the past simple tense, which suggests the action is completed. However, the sentence indicates that the action is still ongoing.
- Option B: has waited → Incorrect because the present perfect tense ("has waited") is used for completed actions that have relevance to the present, but it does not emphasize the continuous nature of the action.
- Option D: had waited → Incorrect because "had waited" is in the past perfect tense, which is used when referring to an action that was completed before another past action. However, this sentence refers to an action that is still ongoing.
Final Answer: Option C: has been waiting.