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: Pharmacology
Chemically aspirin is 
Select and explain. 
A. Acetyl salicylic acid, B. Para-aminosalicylic acid, C. Para-aminobenzoic acid, D. Acetaminophen
A: Acetyl salicylic acid
Answer: A: Acetyl salicylic acid 
Explanation: Ans. is 'a' i.e., Acetyl salicylic acid