This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
What is the best method for confirming amyloidosis :- 
Select and explain. 
A. Colonoscopy, B. Sigmoidoscopy, C. Rectal biopsy, D. Tongue biopsy
C: Rectal biopsy
Answer: C: Rectal biopsy 
Explanation: Answer is C (Rectal biopsy): Rectal biopsy is single best answer amongst the options provided. The systemic amyloidosis offer a choice of biopsy sites. Abdominal fat aspirates or renal or rectal biopsies are often preferred'. - Harrison