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
The process underlying differences in expression of a gene, according to which parent has transmitted, is called: 
Select and explain. 
A. Anticipation, B. Mosaicism, C. Non-penetrance, D. Genomic imprinting
D: Genomic imprinting
Answer: D: Genomic imprinting 
Explanation: None