**Core Concept**
Pervasive Developmental Disorders (PDDs) are a group of neurodevelopmental disorders characterized by delays in the development of multiple basic functions including social interaction, verbal and nonverbal communication, and cognitive processes. These disorders are now referred to as Autism Spectrum Disorder (ASD) in the DSM-5.

**Why the Correct Answer is Right**
The correct answer is not one of the Pervasive Developmental Disorders. PDDs include conditions such as Autistic Disorder, Asperger's Disorder, Rett's Disorder, Childhood Disintegrative Disorder, and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS). Each of these conditions has distinct characteristics, but they all share a common underlying pathology of impaired social interaction, communication, and repetitive behaviors.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is actually one of the Pervasive Developmental Disorders, specifically Autistic Disorder.
**Option B:** This option is also a Pervasive Developmental Disorder, Asperger's Disorder.
**Option C:** This option is another Pervasive Developmental Disorder, Rett's Disorder.

**Clinical Pearl / High-Yield Fact**
It's worth noting that the diagnosis and classification of PDDs have evolved over time, and the current understanding is that Autism Spectrum Disorder (ASD) is a single condition with varying levels of severity and symptom presentation.

**Correct Answer:** D.