Answer:
The right answer is, A. Asistieron.
* Ayer ustedes asistieron al partido de fútbol.
Step-by-step explanation:
Because the sentence indicates that you are speaking in the second person of the plural in referring to a past action, therefore, taking into account the above, it is important to identify the subject, number, gender and time in order to correctly conjugate the verb and be consistent with what is being expressed.