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
Transverse root fracture Healing can be done by : 
Select and explain. 
A. Union of segments with hard tissue., B. Bony ingrowth across the fracture line., C. Interposition of connective tissue or fibrous tissue., D. All of the Above.
D: All of the Above.
Answer: D: All of the Above. 
Explanation: Healing of Root Fracture
According to Andreasen and Hjorting-Hanson, transverse root fracture healing can be done by any one of the following ways:

Union of segments with hard tissue
Interposition of connective tissue or fibrous tissue (periodontal ligament)
Bony ingrowth across the fracture line
Non-union with associated interposition of granulation tissue.