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: Pathology
In lobstein disease or brittle bone disease defect occurs in: 
Select and explain. 
A. Type 1 collagen, B. Type 2 collagen., C. Type 4 collagen., D. Type 6 collagen.
A: Type 1 collagen
Answer: A: Type 1 collagen 
Explanation: Osteogenesis imperfecta is also known as lobstein disease in which defect occurs in type 1 collagen.