Final answer:
The migration west meant that factory owners now employed immigrants.
Step-by-step explanation:
The migration west meant that factory owners now employed immigrants (option a). After the Civil War, the landscape of American labor changed, and the majority of workers were employed by others in factories and offices in the cities. Many immigrants from Northern Europe and Canada were drawn to the promise of employment in the United States and made up a significant number of the urban workforce. These immigrants were willing to work longer hours for less pay, which made them attractive to factory owners.