Answer:
I believe that it is CONDITIONAL TENSE
Explanation:
Frequently, the conditional is used to express probability, possibility, wonder or conjecture, and is usually translated as would, could, must have or probably.
Hope this Helps! :)
Un hecho es algo que ya a sido cumplido o terminado y una opinión es algo que tú piensas o crees sobre otra cosa
The correct word to fill the blank and complete the sentence is, pudieron.
• Ustedes no pudieron ir al concierto anoche. ¿Por qué?