**Core Concept**
The treatment of contacts of meningococcal meningitis involves chemoprophylaxis to prevent the spread of the disease, typically using antibiotics that target Neisseria meningitidis. This approach is crucial in reducing the risk of secondary cases, especially in close contacts such as family members or roommates.

**Why the Correct Answer is Right**
Chemoprophylaxis with antibiotics such as ciprofloxacin, ceftriaxone, or rifampicin is effective in eradicating carriage of N. meningitidis in contacts. These antibiotics work by inhibiting bacterial DNA replication, protein synthesis, or cell wall synthesis, thereby preventing the bacteria from multiplying and causing disease. The use of chemoprophylaxis is particularly important in settings where the risk of secondary transmission is high, such as in households or daycare centers.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not specify a particular antibiotic or treatment regimen.
* **Option B:** This option is incorrect as it does not provide a clear treatment approach for contacts of meningococcal meningitis.
* **Option D:** This option is incorrect as it refers to a treatment for a different type of infection.

**Clinical Pearl / High-Yield Fact**
Chemoprophylaxis with antibiotics should be administered as soon as possible after exposure to N. meningitidis, ideally within 24 hours, to maximize its effectiveness in preventing secondary cases. This is particularly important in outbreaks or epidemics of meningococcal meningitis.

**Correct Answer: C. Ceftriaxone**