【单选题】

Which of the following hypothetical discoveries, if made, would cast MOST doubt on the most recent conclusions regarding the function of the human appendix
A．(A) After laboratory experiments, scientists discover evidence to reject the notion that the human appendix is a "vestigial" organ.

B．(B) Certain animal species which had not previously been given attention are discovered to possess an appendix resembling that of humans.
C．(C) Lymphoid tissue is discovered, after careful study, not to play a role in the recognition of foreign antigens in ingested material.
D．(D) After re-examination of the evidence, ulcerative colitis is discovered to be caused by factors wholly unrelated to the human appendix.
E．(E) It is discovered that in rabbits, hindgut fermentation does not require the presence of an organ acting as reservoir for bacteria.