Choose the correct variant. I am hungry. I ... this morning.

The sentence describes a current state of hunger and relates it to an action (or lack thereof) this morning. The present perfect tense is appropriate here to connect a past action (or inaction) to the present. The subject is 'I', so the auxiliary verb should be 'have'. Therefore, 'haven't had breakfast' correctly completes the sentence, indicating that breakfast was not eaten this morning, leading to current hunger. The other options are grammatically incorrect or do not fit the context.

I haven't had breakfast this morning.