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: Anatomy
Cleft of upper lip is formed due to failure 
Select and explain. 
A. Failure of fusion of maxillary process to mandibular process, B. Medial nasal and two mandibular process, C. Medial nasal and lateral nasal process, D. Medial nasal and maxillary process
D: Medial nasal and maxillary process
Answer: D: Medial nasal and maxillary process 
Explanation: None