Which drug in the list has Amoxicillin as its chemical structure?

• A. Amoxicillin
• B. Cloxacillin
• C. Ampicillin
• D. Benzylpenicillin

Answer: (A)

The essential idea is that chemical structure is unique to each compound. While penicillins share the same core beta-lactam ring, the side chains define the exact molecule. Amoxicillin has a specific side chain that makes its structure distinct from the others. The other drugs listed—cloxacillin, ampicillin, and benzylpenicillin—are different penicillins with different side chains, so their structures do not match amoxicillin. Therefore, the substance with amoxicillin as its chemical structure is the one that is explicitly amoxicillin.