**Core Concept**
Eugen Bleuler's 4As are a set of symptoms associated with schizophrenia, which were first proposed by the Swiss psychiatrist Eugen Bleuler in the early 20th century. The 4As are a fundamental concept in the diagnosis and understanding of schizophrenia, representing the core symptoms of the disorder.

**Why the Correct Answer is Right**
Bleuler's 4As include Autisms (now referred to as negative symptoms), Affect flattening, Ambivalence, and Association disturbances. These symptoms are characteristic of schizophrenia and are used to differentiate it from other psychiatric disorders. Autisms refer to negative symptoms such as social withdrawal, apathy, and lack of motivation, while Affect flattening is a reduction in emotional expression. Ambivalence is the presence of conflicting emotions or thoughts, and Association disturbances refer to disorganized thinking and speech.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not one of Bleuler's 4As.
**Option B:** This option is a correct component of the 4As, representing a fundamental symptom of schizophrenia.
**Option C:** This option is not one of Bleuler's 4As.
**Option D:** This option is a correct component of the 4As, representing a key symptom of schizophrenia.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Bleuler's 4As are not a diagnostic criterion for schizophrenia but rather a way to describe the characteristic symptoms of the disorder. Understanding the 4As can help clinicians differentiate schizophrenia from other psychiatric conditions.

**Correct Answer: B. Affect flattening**