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
Cross-linking in resins helps increasing: 
Select and explain. 
A. Strength, B. Hardness, C. Crazing resistance, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: The resin matrix in most dental composites is based on a blend of aromatic and/or aliphatic dimethacrylate monomers such as bis-GMA and urethane dimethacrylate (UDMA), to form highly cross-linked, strong, rigid, and durable polymer structures.
Anusavice, Shen, Rawls. Phillip’s Science of Dental Materials. Edition 12. Page:​295