**Core Concept**
The prevention of parent-to-child transmission (PPTCT) of HIV is a crucial aspect of reducing the spread of the virus, particularly in high-prevalence regions. NACO's recommendations are based on the latest evidence and guidelines from the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC).

**Why the Correct Answer is Right**
The recommended antiretroviral regimen for PPTCT is a single-dose Nevirapine (NVP) administered to the mother at the onset of labor, followed by a single dose of NVP administered to the newborn within 72 hours of birth. This regimen has been shown to reduce the risk of mother-to-child transmission of HIV by up to 50%. The mechanism of action of NVP involves the inhibition of HIV reverse transcriptase, which prevents the virus from replicating and reducing the viral load.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not align with the current NACO recommendations for PPTCT. While other antiretroviral regimens may be effective, they are not the recommended first-line treatment.
**Option B:** This option is incorrect as it is not a recommended antiretroviral drug for PPTCT. Although it is used in the treatment of HIV, it is not the preferred choice for PPTCT.
**Option C:** This option is incorrect as it is not the recommended regimen for PPTCT. While combination antiretroviral therapy (cART) is essential for the treatment of HIV, it is not the recommended approach for PPTCT.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the effectiveness of PPTCT programs depends on the availability of antiretroviral drugs, healthcare infrastructure, and the ability to provide comprehensive care to HIV-positive pregnant women. A combination of antiretroviral therapy, safe delivery practices, and post-exposure prophylaxis can significantly reduce the risk of mother-to-child transmission of HIV.

**Correct Answer:** Nevirapine (NVP)

✓ Correct Answer: C. Nevirapine 200 mg in active about to mother and syrup nevirapine 2 mg/kg body weight to newborn with 72 hours of delivery