**Core Concept**
The collection of a specimen for diagnosing Neisseria meningitidis (N. meningitidis) infection involves obtaining a cerebrospinal fluid (CSF) sample. This is because N. meningitidis is a bacterium that causes meningitis, an infection of the meninges, the protective membranes surrounding the brain and spinal cord.

**Why the Correct Answer is Right**
The CSF sample is collected through a lumbar puncture (LP), also known as a spinal tap. During an LP, a needle is inserted between two vertebrae in the lower back to collect a sample of CSF. This is the most accurate and reliable site for collecting a specimen for N. meningitidis culture, as the bacterium is typically present in the CSF during an infection. The CSF sample is then sent to a laboratory for culture, Gram staining, and other diagnostic tests.

**Why Each Wrong Option is Incorrect**
**Option A:** Blood is not the best site for collecting a specimen for N. meningitidis, as the bacterium may not be present in the blood during the early stages of infection, and blood cultures may not be as sensitive as CSF cultures.
**Option B:** Urine is not a reliable site for collecting a specimen for N. meningitidis, as the bacterium may not be present in the urine during an infection.
**Option C:** Throat swabs may be used to collect a specimen for N. meningitidis, but they are not the best site for diagnosing meningitis, as the bacterium may not be present in the throat during an infection.

**Clinical Pearl / High-Yield Fact**
When performing a lumbar puncture to collect a specimen for N. meningitidis, it is essential to use sterile technique to prevent contamination of the CSF sample and to minimize the risk of complications.

**Correct Answer: C. Throat swabs may be used to collect a specimen for N. meningitidis, but they are not the best site for diagnosing meningitis, as the bacterium may not be present in the throat during an infection.