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: Pharmacology
Structurally, heparin is : 
Select and explain. 
A. Homopolysaccharide, B. Heteropolysaccharide, C. Glycoprotein, D. Mucoprotein
B: Heteropolysaccharide
Answer: B: Heteropolysaccharide 
Explanation: None