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': 'It is essential to lubricate dam before applying it. Which of these is NOT a suitable lubricant? \nSelect and explain. \nA. Shaving cream, B. Liquid soap, C. Scrub gel, D. Vaseline', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]