**Core Concept**
Pneumococcal meningitis is a severe infection caused by the bacterium *Streptococcus pneumoniae* that requires prompt and adequate antibiotic treatment to prevent complications and reduce mortality. The duration of antibiotic treatment for pneumococcal meningitis is crucial to ensure effective eradication of the pathogen and prevent relapse.

**Why the Correct Answer is Right**
The recommended duration of antibiotic treatment for pneumococcal meningitis is 10-14 days. This prolonged treatment period is necessary to ensure that the antibiotics penetrate the cerebrospinal fluid (CSF) and effectively target the bacteria. The prolonged treatment also helps to prevent the emergence of antibiotic-resistant strains of *S. pneumoniae*. Vancomycin and ceftriaxone are commonly used antibiotics for treating pneumococcal meningitis, and their effectiveness is enhanced by the prolonged treatment duration.

**Why Each Wrong Option is Incorrect**
**Option A:** Some studies suggest a shorter treatment duration, but the majority of guidelines recommend at least 10-14 days of treatment.
**Option B:** This option is too short and may not be sufficient to prevent complications and relapse.
**Option C:** There is no evidence to support a longer treatment duration than 14 days.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the duration of antibiotic treatment for pneumococcal meningitis may vary depending on the patient's clinical response and the presence of any complications. A prolonged treatment duration is crucial to prevent relapse and ensure effective eradication of the pathogen.

**Correct Answer: D. 14 days**