Infantile autism is characterized by -a) Impaired visionb) Impaired Neurobehavioural developmentc) Impaired folate leveld) A socio-economic hazarde) Parenting

**Core Concept**
Infantile autism, also known as Autism Spectrum Disorder (ASD), is a neurodevelopmental disorder characterized by impaired social interaction, communication, and behavior. The core features of ASD involve difficulties in verbal and nonverbal communication, social interactions, and repetitive behaviors or interests.

**Why the Correct Answer is Right**
The correct answer is related to the core features of ASD. Impaired neurobehavioural development is a hallmark of ASD, which affects an individual's ability to communicate, interact, and behave in a typical manner. This impairment is due to differences in brain structure and function, particularly in regions responsible for social cognition, language processing, and motor control. The neurobehavioural deficits in ASD are present from early childhood and can persist into adulthood.

**Why Each Wrong Option is Incorrect**
* **Option A:** Impaired vision is not a characteristic feature of ASD. While some individuals with ASD may have co-occurring visual impairments, vision loss is not a primary diagnostic criterion for the disorder.
* **Option C:** Impaired folate levels are not directly related to the core features of ASD. Folate deficiency can cause neurological symptoms, but it is not a primary cause of ASD.
* **Option D:** A socio-economic hazard is not a direct cause of ASD. While environmental factors, including socio-economic status, may influence the risk of developing ASD, they are not the primary cause of the disorder.
* **Option E:** Parenting style is not a direct cause of ASD. While parenting practices may impact the development and treatment of ASD, they are not a primary cause of the disorder.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that ASD is a heterogeneous disorder with a strong genetic component. Individuals with ASD may have co-occurring medical conditions, such as gastrointestinal issues, sleep disturbances, and seizures, which require comprehensive diagnostic evaluation and management.

**Correct Answer: B. Impaired Neurobehavioural development**