Answer:
The sentence could take the place of: "Tú compras un boleto para ellos" is:
- Se lo compras.
Explanation:
The object pronouns are nouns that have their position in the complement of the sentence, in <em>English</em> these are me, you, him, her, it, us, and them, in <em>Spanish</em> are: me, te, se, and nos, <em>their use is focused to the person who realizes the action for</em>, in this case, it's focused to "ellos" whose object pronoun is "se" and the article that must be used is "lo".
