Final answer:
The family's action of leaving their war-torn country, Syria, is best described as emigration. This refers to the act of leaving one's native country to live in another. The other terms do not accurately describe the family's situation.
Step-by-step explanation:
The scenario described where a family from Aleppo, Syria has left their war-torn country best fits the definition of emigration. Emigration is a term used to describe the act of leaving one's home country with the intent to settle in another country. In this context, it refers to the departure of the family from Syria. It does not factually describe the other options: chain migration refers to when migrants from a particular town follow each other to a new locale, migration stream is a term for ongoing, long-term patterns of international or regional migration, and step migration refers to a migration pattern conceptualized as a step-by-step process where a migrant reaches their ultimate destination via a series of smaller moves. Immigration, while it is certainly part of this family’s journey, is only half of the story as it pertains to entering a new country, while emigration captures the act of them leaving Syria.
Learn more about emigration