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
Which of the following is a true cyst? 
Select and explain. 
A. Aneurysmal bone cyst, B. Gingival cyst of the newborn, C. Haemorrhagic bone cyst, D. All of the above
B: Gingival cyst of the newborn
Answer: B: Gingival cyst of the newborn 
Explanation: None