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
Which of these is not a part of extracellular matrix - 
Select and explain. 
A. Laminin, B. Fibronectin, C. Integrins, D. Collagen
C: Integrins
Answer: C: Integrins 
Explanation: None