**Core Concept**
Schizophrenia is a complex mental disorder characterized by a combination of positive symptoms (e.g., hallucinations, delusions) and negative symptoms (e.g., apathy, social withdrawal). Prognosis in schizophrenia refers to the likelihood of recovery or improvement in symptoms and functional outcomes over time.

**Why the Correct Answer is Right**
Good prognosis in schizophrenia is often associated with the presence of negative symptoms, particularly a lack of flat affect, and a better premorbid adjustment. This is because individuals with a better premorbid adjustment tend to have a more robust social support network and higher cognitive reserve, which can facilitate recovery. Additionally, the presence of negative symptoms may indicate a more chronic but less severe course of illness.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because positive symptoms, such as hallucinations and delusions, are generally associated with a poorer prognosis in schizophrenia. While positive symptoms can be effectively managed with antipsychotic medication, they often persist and can significantly impact daily functioning.
**Option B:** This is incorrect because a family history of schizophrenia is actually associated with a poorer prognosis. Individuals with a family history of schizophrenia may be more likely to experience a more severe and chronic course of illness.
**Option C:** This is incorrect because a lack of social support is actually a risk factor for poorer outcomes in schizophrenia. Individuals with strong social support networks tend to have better outcomes and are more likely to adhere to treatment regimens.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that prognosis in schizophrenia is highly individualized and can be influenced by a range of factors, including premorbid adjustment, social support, and the presence of negative symptoms. Clinicians should strive to identify these factors early in the course of illness to provide targeted interventions and optimize outcomes.

**Correct Answer: C.**