In a hotel, there are four people A. B, C, and D of different occupations and nationalities. They come from four countries: Britain, France, Germany, and the United States. It is now known that Germans are doctors, Americans are the youngest and are police. C is older than the Germans, B is a judge and a friend of the British, and D has never studied medicine. It follows that C is:. ['British.', 'French.', 'Americans.', 'Not sure.']