Answer: The correct answer is : Sir Ector of Morven was Arthur's foster father.
Explanation: Arthur was the king of Great Britain and had to make a sword from a stone in order to prove he was the rightful king. Arhur is the ideal man. Sir Ector was a retired gentleman, he has a son named SIr Kay who is Arthur's adoptive brother, Kay was a liar and assassin whom Arthur turns into his seneschal