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
Which embryonic structure forms philtrum of upper lip 
Select and explain. 
A. Maxillary process, B. Mandibular process., C. Medial nasal process., D. Lateral nasal process.
C: Medial nasal process.
Answer: C: Medial nasal process. 
Explanation: None