Choose the correct subject pronoun (tú, usted, ellos, ellas, ustedes) to complete the sentence. ¿cómo se llama tú usted ustedes ellos

Usted is the right answer

Usted is the correct answer because of the words se and llama. First of all, the word se demands that the question is in formal way or addressed to the third person singular. Since there is no any option for the third person singular, we conclude that the correct answer is usted. So the word llama is the conjugation of the verb llamar that matches the subject pronoun usted. Finally:

¿Cómo se llama usted?