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: Biochemistry
Apo B48 and apo 13,00 are expressed as two different apoproteins because of difference in : 
Select and explain. 
A. RNA editing, B. RNA splicing, C. Chromosomal loci, D. Apo-B gene
A: RNA editing
Answer: A: RNA editing 
Explanation: A i.e. RNA editing