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

The sentence describes an action that started in the past and is still continuing at the present time, as shown by the phrase “He’s still waiting now”.

For such situations, the correct tense is the present perfect continuous tense.

The verb form “has been waiting” correctly expresses an action that began in the past and continues up to the present moment.

The other options do not show this sense of continuity up to the present.

Therefore, the correct answer is Option A – has been waiting.