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: Dental
[{'content': 'Which of the following constituent of reversible hydrocolloid is present in highest amount by weight percent \nSelect and explain. \nA. Water, B. Agar, C. Potassium, D. Sodium', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]