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
During the development of a tooth, sound coalescence of the lobes results in 
Select and explain. 
A. Grooves, B. Fissures, C. Cusps, D. All of the above
A: Grooves
Answer: A: Grooves 
Explanation: None