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
False about enamel rods is 
Select and explain. 
A. They are perpendicular to tooth surface, B. They are parallel to each other, C. Diameter of enamel rods is 30micrometer at DEJ, D. Diameter of enamel rod is 5 micrometer at DEJ
C: Diameter of enamel rods is 30micrometer at DEJ
Answer: C: Diameter of enamel rods is 30micrometer at DEJ 
Explanation: Option C is false as diameter of enamel rod (avg) is 5 micrometer at DEJ and 8 micrometer at surface.