【单选题】The passage provides information in support of which of the following assertions?
A.
Lymphoid tissue somehow involved in the body's ability to recognize foreignantigens in ingested material is a primary cause of ulcerative colitis.
B.
The appendix is an anomaly among mammals, existing in rabbits and humans largely as an evolutionary fluke.
C.
Microscopic research is insufficient to give even the vaguest suggestion of what the human appendix's function may be.
D.
The digestive process in human beings is less dependent on the hindgut fermentation process than is the digestive process in rabbits.
E.
Lymphoid tissue that recognize foreign antigens is absent in the digestive systems of animals that lack appendixes.