Bianca: ¿cuándo supiste que tu padre está de vuelta de su viaje? victoria: lo anoche.

Answer : supe

Victoria: Lo supe anoche.

Explanation : "anoche" is a temporary reference in the past. The action performed by the verb began and ended in the past, so the verb must be conjugated in the preterite tense. Since the subject is Victoria, who is the one who speaks, this is the first singular person, so the verb must be conjugated in this way: "Yo supe".

Translation :

Bianca: When did you know that your father is back from his trip?

Victoria: I knew it last night.