The correct answers are Hugh Capet, William the Conqueror, and Philip Augustus.
Hugh Capet was the son of Hugh the Great, Duke of the Franks and Count of Paris. At the end of the 10th century Hugh Capet was elected King by the prelate of Reims and during his rule, he started a campaign to unite the feudal realms, thus he was in a constant struggle against rebel feudal lords. He founded the House of Capet.
William the Conqueror was Duke of Normandy and therefore a feudal lord. After a long struggle against other feudal lords, he secured and consolidated his power in the region of Normandy, Northern France, which enabled him to start his successful campaign for the conquest of England in 1066. He was the first King of England of Normand origin.
Philip Augustus, a descendant of Hugh Capet, was the King of the Franks (1180-1223), he secured the royal power in front of the feudal lords, extended the throne's power and the royal ideology.
The other three options were not feudal monarchs, Theodosius II was Roman emperor, Justinian was a Byzantine emperor, and Thomas Becket was the Archbishop of Canterbury.
