Which of the following people was of similar status to the pope in the Middle Ages' social hierarchy? bishop vassal king knight

It would be the "king" who was of similar status to the pope in the Middle Ages' social hierarchy, since the Pope oversaw the Catholic Church, which played a great role in government.

The person who had an important role in the social strata of the Middle Ages' and had a similar tatus to the pope would be a king. While popes had power and influence wover the catholic church at the time, kings were running and leading entire countries and kingodms. In a way it could be argued that the power of a pope always outweighed the power of one particular kingdom/king.