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
Simian crease is seen in: 
Select and explain. 
A. Down's syndrome, B. Trisomy of chromosome No.13, C. Cri-du-chat syndrome, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Simian crease is an older name for a condition now more commonly called single transverse palmar crease. It refers to a single crease across the palm of the hand. In most individuals, there are two slightly oﬀset creases across the palm. Simian crease is seen in:

Down's syndrome
Trisomy of chromosome No.13 
Cri-du-chat syndrome