**Core Concept**
Bacitracin is a type of antibiotic that belongs to the polypeptide class. It is used to treat various bacterial infections, particularly those caused by Gram-positive bacteria. Bacitracin works by inhibiting bacterial cell wall synthesis.

**Why the Correct Answer is Right**
Bacitracin specifically targets the enzyme transpeptidase, which is involved in the cross-linking of peptidoglycan layers in the bacterial cell wall. By inhibiting this enzyme, bacitracin prevents the formation of a stable bacterial cell wall, ultimately leading to cell lysis and death. This mechanism of action is unique to bacitracin and is distinct from other antibiotics that target different steps in bacterial cell wall synthesis.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as bacitracin does not act on DNA replication or transcription.
**Option B:** Incorrect, as bacitracin does not inhibit protein synthesis.
**Option C:** Incorrect, as bacitracin does not target the bacterial membrane.

**Clinical Pearl / High-Yield Fact**
It's essential to note that bacitracin is not suitable for parenteral administration due to its potential nephrotoxicity. Topical application, however, is a common use for bacitracin, particularly in ointments and creams for wound care.

**Correct Answer:** C. It inhibits the enzyme transpeptidase, which is involved in bacterial cell wall synthesis.