Final answer:
Labor unions were not a factor in the rise of big business or industrialism; the actual factors were technological advancements, capital investment, and improved transportation.
Step-by-step explanation:
The factor that was NOT one of the factors that led to the rise of big business or industrialism is B. Labor unions. The rise of big business and industrialism in the United States during the late 19th and early 20th centuries was primarily driven by other factors such as technological advancements, significant capital investment, and improved transportation systems. These elements contributed to the transformation of the American economy from an agrarian to an industrial powerhouse. While labor unions played an important role in advocating for workers' rights, they were not a driving force behind the rise of industrialism; rather, they were a response to the conditions created by it.