This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Biochemistry
If the 4% of thymine residues in DNA is 28% what is the % of cystosine 
Select and explain. 
A. 28%, B. 44%, C. 36%, D. 22%
D: 22%
Answer: D: 22% 
Explanation: this is solved acc to chargaff rules = A+T+G+C=100% REF : LIPINCOTT BIOCHEMISTRY