**Core Concept**
The question is testing the student's knowledge of a specific antibiotic that inhibits bacterial protein synthesis and has a narrow spectrum of activity, which is used to treat infections caused by Bacteroides fragilis, but is associated with antibiotic-associated colitis.

**Why the Correct Answer is Right**
The described antibiotic is a chloramphenicol derivative that inhibits protein synthesis by binding to the 50S ribosomal subunit of bacteria. It has a narrow spectrum of activity and is effective against anaerobic bacteria, including Bacteroides fragilis. However, its use is limited due to the risk of aplastic anemia and antibiotic-associated colitis.

**Why Each Wrong Option is Incorrect**
**Option A:** Metronidazole is an antibiotic that is effective against anaerobic bacteria, but it is not a chloramphenicol derivative and does not inhibit protein synthesis.

**Option B:** Clindamycin is a lincosamide antibiotic that inhibits protein synthesis, but it is not specifically used to treat Bacteroides fragilis infections and is associated with a higher risk of antibiotic-associated colitis compared to the described antibiotic.

**Option C:** Cefoxitin is a cephamycin antibiotic that inhibits cell wall synthesis, not protein synthesis, and is not primarily used to treat Bacteroides fragilis infections.

**Option D:** Ampicillin is a penicillin antibiotic that inhibits cell wall synthesis, not protein synthesis, and has a broader spectrum of activity than the described antibiotic.

**Clinical Pearl / High-Yield Fact**
The described antibiotic is a classic example of a narrow-spectrum antibiotic that is effective against specific types of bacteria, but its use is limited due to potential side effects.

**Correct Answer:** C. Clindamycin