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
The predominant isozyme of LDH in cardiac muscle is: 
Select and explain. 
A. LD-1, B. LD-2, C. LD-3, D. LD-5
A: LD-1
Answer: A: LD-1 
Explanation: LD-1 is the predominant isoenzyme of LDH in cardiac muscle. Ref: Harper's Principles of Internal Medicine, 26th Edition, Page 57; Textbook of Biochemistry By Vasudevan, 5th Edition, Page 53