Final answer:
The plan that called for hiring experts in their fields to run a single aspect of society is known as the Progressive Reform Plan.
Step-by-step explanation:
The plan that called for hiring experts in their fields to run a single aspect of society is known as the Progressive Reform Plan. During the Progressive Era in the early 20th century, reformers believed that by placing experts in charge of government and management, efficiency and accountability could be improved.
This plan aimed to end corruption and patronage systems and replace them with specialized departments headed by experts. By doing so, they hoped to decentralize power and ensure that decisions were made by individuals with the knowledge and skills necessary to address specific issues.