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
In transitional phase of secretory stage: 
Select and explain. 
A. Ameloblasts undergo apoptosis, B. 25% of cells die during transitional phase, C. Cell volume and organelle decreases, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Transitional Phase of the Presecretory Stage

Ameloblasts undergo significant morphological changes.
Height of cell reduces.
Cell volume and organelle decreases.
Ameloblasts undergo programmed cell death (Apoptosis)
25 of cells die during during transitional phase.