**Core Concept**
Vancomycin is a glycopeptide antibiotic that primarily targets gram-positive bacteria. Its mechanism of action is distinct from other antibiotics, making it a critical aspect of antibiotic therapy.

**Why the Correct Answer is Right**
Vancomycin acts by inhibiting cell wall synthesis in gram-positive bacteria, not by inhibiting bacterial protein synthesis. It binds to the D-alanyl-D-alanine terminus of cell wall precursors, preventing the incorporation of these precursors into the bacterial cell wall, ultimately leading to bacterial cell lysis. This mechanism is distinct from antibiotics that inhibit protein synthesis, such as aminoglycosides or tetracyclines.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is true, as vancomycin is indeed a bactericidal antibiotic that is active primarily against gram-positive bacteria.
**Option C:** This statement is also true, as vancomycin is often used as an alternative to penicillin for treating enterococcal endocarditis, particularly in cases where penicillin resistance is a concern.
**Option D:** This statement is true, as high doses of vancomycin can cause ototoxicity, including hearing loss.

**Clinical Pearl / High-Yield Fact**
Remember that vancomycin is a time-dependent antibiotic, meaning its effectiveness depends on maintaining adequate serum concentrations for a sufficient duration. This is in contrast to aminoglycosides, which are concentration-dependent antibiotics.

**✓ Correct Answer:** B. It acts by inhibiting bacterial protein synthesis