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 of the following prominence is unpaired: 
Select and explain. 
A. Frontonasal, B. Maxillary, C. Mandibular, D. None of the above
A: Frontonasal
Answer: A: Frontonasal 
Explanation: The frontonasal prominence is a single unpaired structure; the other prominences are paired. Ref: Langman's embryology 11th edition Chapter 16.