How do you say "i was riding a horse" in spanish and would it be in the preterite or imperfect tense?

Question 2(multiple choice worth 1 points) read the sentence and choices, and then select the choice with the correct words to complete the sentence. —mis hermanos son emilio y arturo. son —¿cómo es emilio? —es altos; pelirrojo altas; pelirrojas altos; pelirroja altas; pelirrojas