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: Biochemistry
[{'content': 'Hexose sugar is not present in: \nSelect and explain. \nA. Ribose, B. Glucose, C. Fructose, D. Galactose', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hexose sugar is present in:Glucose, "blood sugar", the immediate source of energy for cellular respirationGalactose, a sugar in milk (and yogu), andFructose, a sugar found in honeyRibose is a pentose sugar', 'role': 'assistant'}]