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 estimation of 3-methyl histidine in urine is used to study: 
Select and explain. 
A. Status of folate in the body, B. Renal disease, C. Skeletal muscle mass, D. Protein absorption in the gut
C: Skeletal muscle mass
Answer: C: Skeletal muscle mass 
Explanation: Skeletal muscle mass