Answer: Aquel
Step-by-step explanation:
Wich of the following is an adjetive?
1) éste: when this word does not have an accent marker, it is an adjetive, in this case, this is a pronoun.
2) esto, this is an adverb.
3) aquel, this is an adjetive, it used to talk about something that is far away and sinalize it.
"Aquel auto", "Aquel perro"
Aquel is an adjetive demostrative