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
Mentalis muscle contraction causes the lower lip to 
Select and explain. 
A. Retrude, B. Protrude, C. Inversion, D. Eversion
B: Protrude
Answer: B: Protrude 
Explanation: None