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: Physiology
[{'content': 'Faecal mass is mainly derived from: March 2005 \nSelect and explain. \nA. Undigested food, B. Digested food, C. Intestinal secretions, D. intestinal flora', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: Undigested foodFaeces normally are about 3/4th water and 1/4th solid waste.Solid water is composed of:About 30% dead bacteria30% undigested roughage from the food and dried constituents of digestive juices.10-20% fat10-20% inorganic matter2-3% protein', 'role': 'assistant'}]