Final answer:
Pope Urban II is asking who should take on the task of avenging the wrongs done to Christians and recovering the lost territory.
Step-by-step explanation:
Pope Urban II, in lines 21-23, is asking who should take on the task of avenging the wrongs done to Christians and recovering the lost territory. In this context, the wrongs and lost territory refer to the persecutions and conquests of the Seljuk Turks in the Holy Land. Pope Urban II is urging the audience, which is likely made up of Christians, to take up arms and participate in what would later be known as the First Crusade.