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: Medicine
Which is the most common cytogenetic abnormaltiy in adult myelodysplastic syndrome (MDS) - 
Select and explain. 
A. Trisomy 8, B. 20q-, C. 5q-, D. Monosomy 7
D: Monosomy 7
Answer: D: Monosomy 7 
Explanation: None