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: Unknown
Carbamoyl phosphate synthase - 1 acts on - 
Select and explain. 
A. Ornithine, B. Carbamoyl phosphate, C. CO2 & ammonia, D. Arginine
C: CO2 & ammonia
Answer: C: CO2 & ammonia 
Explanation: Ans. is 'c' i.e, CO2 & ammonia o Explained