Final answer:
In 'Le Morte d'Arthur,' other people are given the chance to pull the sword from the stone to ensure that Arthur is indeed the worthy king, as confirmed by divine will and acknowledged by the nobility.
Step-by-step explanation:
In Le Morte d'Arthur, after Arthur pulls the sword from the stone, other people are given a chance to pull it between Christmas and Pentecost to find a worthy king. This period allows the nobility to witness and accept the miraculous event, thereby legitimizing Arthur's claim to the throne. The extended timeframe serves to verify the divine will and ensure that all have seen the chosen one is able to accomplish the feat, fostering acceptance of Arthur's right to be king.
The tradition of testing the right to kingship through divine signs or tasks is common in Arthurian literature, and by extending the period, there's a reaffirmation of both Arthur's unique ability and the fairness of the process. Hence, the correct answer to the student's question is c) To find a worthy king.