Final answer:
A greenstick fracture is an incomplete fracture that passes only partway through the shaft of a bone but may still cause severe angulation.
Step-by-step explanation:
The correct answer is A. greenstick. A greenstick fracture is an incomplete fracture that passes only partway through the shaft of a bone but may still cause severe angulation. This type of fracture is common in children because their bones are more flexible and prone to bending rather than breaking completely. An example of a greenstick fracture would be a bone that is partially cracked but not fully broken.