Which of the following is an antibiotic?

Correct answers: (a) Penicillin or (e) None of the above/More than one of the above

Explanation

Penicillin is an antibiotic, and sulfadiazine is a sulfonamide, a synthetic antibacterial drug; the book counts both and gives "More than one of the above".

Aspirin and paracetamol relieve pain and fever and do not act on bacteria.

In the strict sense (a substance made by a microorganism), only penicillin is an antibiotic; the book also counts sulfadiazine and gives (e). Both are accepted here.