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
A dens in dente is usually caused by: 
Select and explain. 
A. An abnormal proliferation of pulp tissue, B. Denticle formation within the pulp tissue, C. A deep invagination of the enamel organ during formation, D. A supernumerary tooth bud enclaved within a normal tooth.
C: A deep invagination of the enamel organ during formation
Answer: C: A deep invagination of the enamel organ during formation 
Explanation: None