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
Tensile strength of wound after laparoscopic cholecystectomy in a 30 years old woman depends upon: 
Select and explain. 
A. Replacement of type 3 collagen, B. Extensive crosslinking of tropocollagen, C. Macrophage activity/invasion, D. Granulation tissue
B: Extensive crosslinking of tropocollagen
Answer: B: Extensive crosslinking of tropocollagen 
Explanation: The recovery of tensile strength results from the excess of collagen synthesis over collagen degradation during the first 2 months of healing, and, at later times, from structural modifications of collagen fibers (cross-linking, increased fiber size) after collagen synthesis ceases.