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
Carbamoyl phosphate synthase I is used in ? 
Select and explain. 
A. Purine synthesis, B. Pyrimidine synthesis, C. Urea cycle, D. Uronic acid pathway
C: Urea cycle
Answer: C: Urea cycle 
Explanation: Ans. is 'c' i.e., Urea cycleCarbamyl phosphate synthase I Urea cycleCarbamyl phosphate synthase II- Pyrimidine synthesis