Final answer:
Ashkenazi Jews left their countries due to religious persecution and discrimination.
Step-by-step explanation:
The Second Wave immigrants, specifically Ashkenazi Jews, left their countries mainly due to D) Religious persecution and discrimination. Jewish people faced discrimination and anti-Semitism, which led to waves of violence called pogroms in the Russian empire. In order to escape this religious persecution, many Ashkenazi Jews immigrated to the United States.