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
Morphological stages of tooth development are explained based on: 
Select and explain. 
A. Shape of enamel organ, B. Shape of tooth germ, C. Functions of enamel organ, D. Shape of dental papilla
A: Shape of enamel organ
Answer: A: Shape of enamel organ 
Explanation: Morphological stages of tooth development, i.e. bud, cap and bell stage are named after the shape of enamel organ.