detailed solution

Correct option is D

• Antibiotics, which kill or inhibit a wide range of Gram-positive and Gram-negative bacteria are said to be broad spectrum antibiotics. 
• Those effective mainly against Gram-positive or Gram-negative bacteria are narrow spectrum antibiotics. 
• If effective against a single organism or disease, they are referred to as limited spectrum antibiotics. 
• Penicillin G has a narrow spectrum. 
• Ampicillin and Amoxycillin are synthetic modifications of penicillins. 
• These have broad spectrum.