Final answer:
Western Expansion was not a factor that led to the rise of political machines, which were influenced by urban challenges like overcrowding, pollution, and crime.
Step-by-step explanation:
The feature that did NOT lead to the rise of political machines was B. Western Expansion. Political machines were urban phenomena that thrived on the social and economic challenges within cities - such as overcrowding, pollution, and crime. Western Expansion does not directly relate to these urban issues but instead pertains to the growth of the United States towards the west, which, while impactful on a national scale, was not a direct factor in the development of political machines within the urban context.