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
In elevation of the eyebrows and production of transverse wrinkles of the face 
Select and explain. 
A. Only the occipital bellies of occipitofrontalis act, B. Only the frontal bellies of occipitofrontalis act, C. Both the bellies act simultaneously, D. Both the bellies act one after the other
C: Both the bellies act simultaneously
Answer: C: Both the bellies act simultaneously 
Explanation: None