This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
Extra layer of cilia posterior to grey line 
Select and explain. 
A. Tylosis, B. Madarosis, C. distichiasis, D. Trichiasis
C: distichiasis
Answer: C: distichiasis 
Explanation: REF : AK KHURANA 7TH ED