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 of following techniques is used for detection of variations in DNA sequence and Gene expression: 
Select and explain. 
A. Nohern Blot, B. Southern Blot, C. Western Blot, D. Microarray
D: Microarray
Answer: D: Microarray 
Explanation: D i.e. Microarray DNA Microarrays (DNA-Chips) is used for detection or screening of variations in DNA sequences and gene expressionQ analysizing thousands of gene at a same time.