**Core Concept**
The child's presentation of mental retardation and spastic limbs in the context of perinatal distress suggests a condition involving brain damage due to lack of oxygen at birth. This condition is characterized by cerebral palsy, intellectual disability, and other related developmental issues.

**Why the Correct Answer is Right**
The correct diagnosis in this case is Cerebral Palsy (CP), which is a group of permanent disorders that appear in early childhood and are associated with damage to the developing brain, often due to lack of oxygen at birth (perinatal asphyxia). CP can result from various factors, including perinatal distress, premature birth, or infection during pregnancy. The brain damage associated with CP leads to impaired motor control, muscle tone, and coordination, resulting in spastic limbs and intellectual disability.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not directly relate to the child's presentation of cerebral palsy and intellectual disability. While it's a possible cause, it's not the most accurate diagnosis based on the given symptoms.
* **Option B:** This option is incorrect because it's a condition that affects the development of the brain and spinal cord in the fetus, but it's not the primary cause of the symptoms described.
* **Option C:** This option is incorrect because it's a condition that affects the development of the brain and nervous system in the fetus, but it's not directly related to the child's presentation of cerebral palsy and intellectual disability.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that cerebral palsy is a non-progressive condition, meaning that the brain damage is already present at birth and will not worsen over time. Early identification and intervention can significantly improve the child's quality of life and functional abilities.

**Correct Answer:** C. Cerebral Palsy.