Question: Which opera had more acts,  Il trovatore or Attila?
Sentence (from "Attila (opera)"): Attila is an opera in a prologue and three acts by Giuseppe Verdi to an Italian libretto by Temistocle Solera, based on the 1809 play "Attila, König der Hunnen " ("Attila, King of the Huns") by Zacharias Werner.
Relevant evidence: Yes