For the first sentence, the correct answer is<em><u>"contestar"</u></em>. Because, in Spanish <em>when someone picks up the phone</em>, the verb that describes the action is "<em>contestar</em>". The word "<em>auricular</em>" is referring to a ringing cellphone, so in that case, somebody would <em>answer</em> <em>(contestar</em>) that call.<em> Note that</em> the word "<em>auricular</em>" is in disuse in Spanish by young people, for they wouldn't refer to cellphones by the name "<em>auricular</em>" anymore.
For the second sentence, the correct answer is "<em><u>teléfono</u></em>". Because the complete word of the cellphone in Spanish is <em>"teléfono celular", </em>in contrast with wired phone that was in home or in public place but you couldn't take it everywhere.
For the third sentence, the correct answer is "<em><u>cuelgo</u></em>". Because when a conversation is over by cellphone in English you say: <em>"Hang up the phone"</em> as they do in Spanish by using the same verb <em>"colgar"</em>. Now, as the noun is the first person singular, then the conjugation of the verb "<em>colgar</em>" has to be also like that, and therefore the correct answer is <em><u>"cuelgo".</u></em>
Esdrújulas. La sílaba antepenúltima, o tercera desde el final, en Esdrjulas tiene un acento ortográfico. No hay excepciones al acento escrito en estos términos.