Clarification:
I found the instructions for the exercise online and you have to answer the question using a direct object pronoun.
Answer:
No, no nos vio / Sí, nos vio.
Step-by-step explanation:
In this exercise, you have to answer the question using a direct object pronoun.
Direct object pronouns (''pronombres de objeto directo'' in Spanish) are used to replace a direct object, which is a noun, so you do not have to repeat the noun. In this case, nos is in the first person, plural form.