In medieval european society, was the king or the pope the most powerful figure? the king, because the church had no control over armies.
the pope, because the church was wealthier than most kings.
neither, because the power dynamic shifted between the church and the kings.
neither, because the military was more powerful than both kings and popes

The best and most correct answer among the choices provided by the question is third choice "Neither, because the power dynamic shifted between the Church and the kings. "
Moreover, throughout the Middle Ages the Pope claimed the right to depose the Catholic kings of Western Europe, and tried to exercise it, sometimes successfully, sometimes not, as with Henry VIII of England and Henry III of Navarre.

I hope my answer has come to your help. God bless and have a nice day ahead!

The answer is option c.