Which word best completes the conversation?
carla: ayer te mandé un correo electrónico. ¿lo
jaime: sí, recibí tu correo electrónico.
answer choices:
*mandaste*recibieron*mandaron*rec ibiste

This is a conversation between two persons, Carla and Jaime.

Where Carla makes a question in past, we know this because of the word ayer (yesterday) at the beginning of the sentence and because the verb mandar (to send) is written in past as mandé (I sent):

Ayer te mandé un correo electrónico (Yesterday I sent you an email)

Now, if you send something to someone, that thing must be received. Therefore, the correct verb is recibiste in past.

The complete conversation is:

Yesterday I sent you an email. Did you receive it?

Jaime: Sí, recibí tu correo electrónico.

Yes, I received your email

The options mandaste (you sent), recibieron (you received - in plural) and mandaron (you sent - in plural) are incorrect because although are in past tense they do not match with the personal pronoun of the sentence, which is tú (you).