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
[{'content': 'What is the best method for confirming amyloidosis :- \nSelect and explain. \nA. Colonoscopy, B. Sigmoidoscopy, C. Rectal biopsy, D. Tongue biopsy', 'role': 'user'}, {'content': "Answer: C \nExplanation: 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", 'role': 'assistant'}]