Final answer:
In stories of King Arthur, the theme that family members treat one another with special regard is best exemplified by Arthur granting Sir Ector's wish to make Sir Kay Royal Seneschal, option (B).
Step-by-step explanation:
The question relates to the theme of how family members treat one another with special regard in the stories about the court of King Arthur. Exploring the options provided:
(A) Sir Kay asking Arthur for a favor indicates reliance and trust within a family, yet it doesn't sufficiently highlight the theme of special regard more than everyday dependability.
(B) Arthur fulfilling Sir Ector's wish to make Sir Kay Royal Seneschal is a strong example of treating a family member with special honor and respect.
(C) Riding together to the tournament may show family unity, but again, it may not distinctly convey a special regard.
(D) Sir Kay admitting Arthur took the sword from the stone shows honesty and integrity in acknowledging a family member's significant accomplishment.
Considering the actions that best support the theme of special regard within a family, option (B) stands out because Arthur granting a position of high status to Sir Kay at the request of Sir Ector exemplifies special treatment and respect within the family. Thus, the correct option in the final answer is (B).