**Core Concept**
Neuroleptic Malignant Syndrome (NMS) is a life-threatening neurological disorder associated with the use of antipsychotic medications. It is characterized by a combination of hyperthermia, muscle rigidity, autonomic dysfunction, and altered mental status.

**Why the Correct Answer is Right**
The correct answer is related to the laboratory findings that reflect the clinical manifestations of NMS. One of the key laboratory findings in NMS is the elevation of serum creatine kinase (CK) levels, which indicates muscle damage and rhabdomyolysis. Additionally, elevated white blood cell count (leukocytosis) and increased levels of liver enzymes (such as AST and ALT) may also be present. These laboratory findings correlate with the muscle rigidity, hyperthermia, and autonomic dysfunction observed in NMS.

**Why Each Wrong Option is Incorrect**
**Option A:** Elevated serum lactate levels may be seen in NMS, but they are not as specific or sensitive as elevated CK levels for diagnosing the condition.
**Option B:** Electrolyte imbalances may be present in NMS, but they are not the primary laboratory finding that reflects the clinical manifestations of the condition.
**Option C:** Normal serum CK levels do not rule out NMS, as some patients may not have elevated CK levels initially.

**Clinical Pearl / High-Yield Fact**
In patients with NMS, it is essential to monitor serum CK levels, as they can rise rapidly and indicate the need for close monitoring and potential treatment with medications such as dantrolene.

**Correct Answer: C. Normal serum CK levels do not rule out NMS, as some patients may not have elevated CK levels initially.