**Core Concept**
Congenital CMV infection is a leading cause of birth defects and perinatal morbidity worldwide. It is the most common congenital viral infection, affecting approximately 1% of live births.

**Why the Correct Answer is Right**
CMV infection during pregnancy can lead to congenital CMV, which presents with a range of symptoms, including petechial rash, hepatosplenomegaly, microcephaly, and yellow extremities. The virus can be transmitted from the mother to the fetus through the placenta, resulting in a range of clinical manifestations. The diagnosis of congenital CMV is often made based on a combination of clinical findings, laboratory tests, and imaging studies.

**Why Each Wrong Option is Incorrect**
**Option B:** Rubella infection during pregnancy can also lead to congenital rubella syndrome, but the classic triad of symptoms includes deafness, cataracts, and congenital heart disease. The petechial rash and hepatosplenomegaly seen in this case are not typical of congenital rubella syndrome.
**Option C:** HSV (Herpes Simplex Virus) can cause neonatal herpes, which typically presents with skin, eye, and mouth lesions, as well as systemic symptoms such as fever and respiratory distress. The clinical findings in this case do not match those of neonatal HSV.
**Option D:** Varicella (chickenpox) can cause congenital varicella syndrome if the mother contracts the infection during pregnancy, but the typical symptoms include limb hypoplasia, eye abnormalities, and skin scarring. The clinical findings in this case do not match those of congenital varicella syndrome.

**Clinical Pearl / High-Yield Fact**
Congenital CMV infection is often asymptomatic at birth, but affected infants are at increased risk of developing hearing loss, developmental delay, and visual impairment later in life. Early detection and diagnosis are crucial to prevent long-term sequelae.

✓ Correct Answer: A. CMV.