**Core Concept**
Rifampicin is a broad-spectrum antibiotic that belongs to the rifamycin class, primarily used to treat tuberculosis (TB) and other mycobacterial infections. It's a potent inhibitor of bacterial DNA-dependent RNA polymerase, which is essential for bacterial RNA synthesis.

**Why the Correct Answer is Right**
Option B is incorrect because rifampicin is not the primary treatment for meningococcal meningitis. The mainstay of treatment for meningococcal meningitis involves third-generation cephalosporins, such as cefotaxime or ceftriaxone, which are effective against Neisseria meningitidis. Rifampicin may be used as prophylaxis for close contacts of individuals with meningococcal meningitis to prevent secondary cases.

**Why Each Wrong Option is Incorrect**
**Option A:** Rifampicin is indeed a microsomal enzyme inducer, which means it increases the expression of certain enzymes involved in the metabolism of other drugs, potentially leading to decreased efficacy or increased toxicity of those medications.
**Option C:** Rifampicin is known to interact with oral contraceptive pills (OCPs) by inducing the cytochrome P450 enzyme system, which metabolizes estrogens and progestins. This can lead to reduced levels of these hormones, increasing the risk of contraceptive failure.
**Option D:** Rifampicin is indeed bactericidal in nature, meaning it directly kills bacteria by inhibiting RNA synthesis.

**Clinical Pearl / High-Yield Fact**
Rifampicin can cause a harmless but noticeable discoloration of body secretions, such as saliva, sweat, and urine, due to its lipophilic nature and ability to bind to melanin.

**✓ Correct Answer: B. Used in treatment of meningiococcal meningitis**