Narrow range of drugs act against which organisms?

• A. Fungi
• B. Gram positive
• C. Gram positive and Gram negative
• D. Gram negative

Answer: (C)

Narrow-spectrum antibiotics target a limited group of organisms rather than a wide range. That limited range can include bacteria from both major classes, so some narrow-range drugs act against Gram-positive organisms and others against Gram-negative ones, and in some cases cover a small subset within both groups. The option that reflects this idea—that the drugs have activity against Gram-positive and Gram-negative organisms—best fits the concept of a narrow range. This is distinct from targeting fungi or from broad-spectrum agents that cover many bacteria across both groups.