Studies have shown that diabetes is a metabolic disease characterized by chronic hyperglycemia caused by multiple etiologies. It is the result of a combination of factors and has a family aggregation phenomenon. Family history is an important basis for indicating the risk of diabetes. Understanding family history can help prevent diabetes better. What premise must be added to reach the above conclusion? ['The phenomenon of family aggregation is reflected in family history.', 'Understanding the risk of diabetes can help prevent it.', 'Most people have access to their family history.', 'Unhealthy lifestyle is also a factor affecting the onset of diabetes.']