Correct answer:
c. entregaste
This sentence stands for the preterite tense. This tense is one of two simple past tenses. It is used to describe actions that took place or were completed at a certain point in the past. So the question stands for the second person singular and its conjugation is entregaste. On the other hand, the reply of Sofía stands for the first person singular and its conjugation is entregué. Finally:
María: ¿Cuándo entregaste la tarea, Sofía?
Sofía: Entregué la tarea ayer