**Bacteriostatic Drugs**

**Core Concept**
Bacteriostatic drugs are antimicrobials that inhibit the growth and replication of microorganisms, but do not necessarily kill them. This is in contrast to bactericidal drugs, which directly kill the microorganisms.

**Why the Correct Answer is Right**
The correct answer is an example of a bactericidal drug, meaning it directly kills bacteria rather than inhibiting their growth. This is achieved through mechanisms such as disrupting cell wall synthesis, interfering with protein synthesis, or damaging the bacterial cell membrane. In contrast, bacteriostatic drugs typically work by interfering with protein synthesis, cell wall synthesis, or DNA replication.

**Why Each Wrong Option is Incorrect**
**Option A:** This drug works by inhibiting protein synthesis through the formation of a 50S ribosomal subunit-streptolidin complex, which is a bacteriostatic mechanism.
**Option B:** This drug works by inhibiting the synthesis of the bacterial cell wall, leading to cell lysis and death, which is a bactericidal mechanism.
**Option C:** This drug works by inhibiting the synthesis of DNA, leading to cell death, which is a bactericidal mechanism.

**Clinical Pearl / High-Yield Fact**
When choosing between bacteriostatic and bactericidal drugs, it's essential to consider the severity of the infection and the patient's overall health. Bacteriostatic drugs are often used in mild to moderate infections, while bactericidal drugs are used in more severe or life-threatening infections.

**Correct Answer: D.**