**Core Concept**
Social deviance refers to behaviors or characteristics that violate the norms and expectations of a society or culture. In the context of public health and social medicine, social deviance can be used to understand and address various health-related issues.

**Why the Correct Answer is Right**
Suicide is considered a social deviance because it represents a deliberate and intentional act that goes against societal norms and expectations. Unlike other options, which may be related to individual circumstances or external factors, suicide is a behavior that is often stigmatized and viewed as unacceptable by society. This is reflected in the cultural and societal responses to suicide, which often emphasize the need for support and intervention to prevent such behaviors. In contrast, illiteracy, migration, and child abandonment are complex issues with multiple contributing factors, but they are not typically viewed as social deviances in the same way as suicide.

**Why Each Wrong Option is Incorrect**
**Option B:** Illiteracy is a significant public health issue, but it is not necessarily considered a social deviance. Illiteracy is often viewed as a result of various factors, including lack of access to education, poverty, and systemic inequalities, rather than a deliberate act that violates societal norms.

**Option C:** Migration is a complex and multifaceted issue that can be driven by various factors, including economic, social, and environmental factors. While migration can have significant social and health implications, it is not typically viewed as a social deviance.

**Option D:** Child abandonment is a serious social and health issue, but it is often viewed as a result of underlying factors such as poverty, lack of support systems, and mental health issues, rather than a deliberate act that violates societal norms.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize that social deviance can be a complex and multifaceted concept, and that behaviors like suicide often have underlying contributing factors that need to be addressed through a comprehensive and nuanced approach.

**✓ Correct Answer: A. Suicide**