Why does the author have Sir Ector's group make speaking errors in "Arthur Becomes King of Britain"?

The right answer for the question that is being asked and shown above is that: "B. to show humorously that they are simple country folk."

These are the following choices:

A. to make fun of people who are not educated

B. to show humorously that they are simple country folk

C. to show his superiority to those who speak poorly

D. to suggest that only heroes speak well in legends