What is the reason for depicting K as “feeling stupid” when hearing words such as morality, responsibility?

What is the reason for depicting K as “feeling stupid” when hearing words such as morality, responsibility?
A.Because K is a being whose simple way of living questions the definition of social and natural aspects of human being.
B.Because K is depicted as a simple person to show the meaning of the simplest existence as a human being.
C.Because K does not like being cornered.
D.Both a and b.
正确答案：D