Final answer:
The correct preterite conjugation of the verb trabajar is trabajaste.
Step-by-step explanation:
The correct preterite conjugation of the verb trabajar in the sentence is trabajaste.
In Spanish, the preterite is used to talk about completed actions in the past. To conjugate regular -ar verbs like trabajar in the preterite, you remove the -ar ending and add the appropriate ending for the subject. In this case, the subject is tú, so you add the -aste ending to trabaj-.
Example: Tú trabajaste ocho horas ayer. (You worked eight hours yesterday.)
Learn more about Conjugation of the verb trabajar in the preterite tense