In the 1930s, there was a reform era that resulted in:

The correct answer is A. Community-based policing.

Explanation: In the 1930s, there was a significant shift in policing philosophies, focusing on community relations and preventative measures rather than just enforcement. This era emphasized engaging with the community to address issues collaboratively, leading to the development of community-based policing concepts. The other options, such as “get tough on crime” and “the creation of problem-solving courts,” became more prominent in later years.