**Core Concept**
Chicken pox, also known as varicella, is a highly contagious viral infection caused by the varicella-zoster virus (VZV). It primarily affects children and is characterized by a characteristic rash, fever, and malaise.

**Why the Correct Answer is Right**
The secondary attack rate of chicken pox refers to the probability of developing the disease after exposure to an infected individual. The correct secondary attack rate is approximately 90% in susceptible individuals, not 60%. This is due to the high contagiousness of the varicella-zoster virus, which is spread through respiratory droplets, direct contact with infected individuals, or contaminated surfaces.

**Why Each Wrong Option is Incorrect**
**Option A:** The causative agent of chicken pox is indeed the varicella-zoster virus (VZV), which is a member of the herpesvirus family. This statement is true.
**Option B:** The incubation period (IP) of chicken pox is typically 14-16 days, making this statement true.
**Option D:** The rash associated with chicken pox indeed spares the palms and soles, making this statement true.

**Clinical Pearl / High-Yield Fact**
Chicken pox is a self-limiting disease, but it can lead to serious complications, such as secondary bacterial infections, pneumonia, and encephalitis, particularly in immunocompromised individuals.

**✓ Correct Answer: C. Secondary attack rate is about 60%**