**Core Concept**
Schizophrenia is a chronic mental disorder characterized by a combination of positive and negative symptoms. Positive symptoms are those that add to or distort normal behavior, such as hallucinations or delusions, whereas negative symptoms are those that subtract from normal behavior, such as apathy or lack of emotion.

**Why the Correct Answer is Right**
Anhedonia, or the inability to experience pleasure, is a classic negative symptom of schizophrenia. It is often described as a "flat affect" or a lack of emotional response to normally pleasurable activities. Anhedonia is thought to result from abnormalities in the brain's reward system, particularly in the dopamine and serotonin pathways. This is in contrast to positive symptoms, which are often associated with overactivity in these same pathways.

**Why Each Wrong Option is Incorrect**
**Option A:** Ambivalence is a positive symptom of schizophrenia, characterized by a mixed or contradictory emotional state, often manifesting as indecision or conflicting desires.
**Option B:** Automatic obedience, also known as echolalia, is a positive symptom of schizophrenia, where an individual mindlessly repeats the words or actions of another person.
**Option D:** Delusion is a positive symptom of schizophrenia, characterized by a fixed, false belief that is not responsive to reason or evidence.

**Clinical Pearl / High-Yield Fact**
It's essential to distinguish between positive and negative symptoms of schizophrenia, as the former often respond to antipsychotic medication, whereas the latter may require additional treatment, such as mood stabilizers or antidepressants.

**✓ Correct Answer: C. Anhedonia**