**Core Concept**
Congenital varicella syndrome is a rare condition that occurs when a fetus is infected with the varicella-zoster virus during pregnancy, typically between 13 and 20 weeks of gestation. This infection can lead to various congenital anomalies, including limb hypoplasia and scarring.

**Why the Correct Answer is Right**
Varicella-zoster virus (VZV) is a herpesvirus that causes chickenpox in children and shingles in adults. When a pregnant woman contracts VZV, the virus can cross the placenta and infect the fetus, leading to congenital varicella syndrome. The infection can cause damage to the developing fetus, resulting in limb hypoplasia (underdevelopment) and scarring, among other anomalies. The exact mechanism of limb hypoplasia is not fully understood, but it is thought to be related to the virus's effect on the developing limb buds.

**Why Each Wrong Option is Incorrect**
**Option A:** Toxoplasmosis is a parasitic infection that can also be transmitted to the fetus during pregnancy, but it typically causes different congenital anomalies, such as hydrocephalus and chorioretinitis.
**Option B:** Rubella infection during pregnancy can cause congenital rubella syndrome, which includes a range of anomalies, including deafness, cataracts, and heart defects, but not typically limb hypoplasia and scarring.
**Option C:** Cytomegalovirus (CMV) infection during pregnancy can cause congenital CMV disease, which includes hearing loss, developmental delays, and vision problems, but not typically limb hypoplasia and scarring.
**Option D:** Herpes simplex virus (HSV) infection during pregnancy can cause neonatal herpes, but it is not typically associated with congenital anomalies such as limb hypoplasia and scarring.

**Clinical Pearl / High-Yield Fact**
It's essential to diagnose and manage varicella-zoster virus infection promptly in pregnant women, especially during the first 20 weeks of gestation, to minimize the risk of congenital varicella syndrome.

**Correct Answer:** C. Cytomegalovirus (CMV) infection is not the correct answer; however, the provided options were incomplete. A more accurate multiple-choice question would be:

**Question:** Which of the following infections acquired during pregnancy result in hypoplasia of limbs and scarring in the fetus?

A. Toxoplasmosis
B. Rubella
C. Varicella-zoster virus
D. Herpes simplex virus

**Correct Answer:** C. Varicella-zoster virus