This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Biopsy of which of the following is usually taken for the diagnosis of systemic amyloidosis- 
Select and explain. 
A. Stomach, B. Duodenum, C. IIeum, D. Rectum
D: Rectum
Answer: D: Rectum 
Explanation: Harshmohan textbook of pathology 7th edition. In systemic amyloidosis renal biopsy provides the best detection rate but rectal biopsy also has a good pickup rate. However gigiva and skin biopsy have poor result..