Final answer:
Rachel's ideas align with Structural Functionalism, which sees society as a stable system where all parts work together for mutual benefit.
Step-by-step explanation:
Rachel's belief that all parts of a society work together for the benefit of the whole aligns with the Structural Functionalism perspective in sociology. This theoretical framework posits that all aspects of a society are structured in such a way that they serve a function and work together to maintain the stability and functionality of the whole society. Structural functionalism views society as having a system of interdependent inherently connected parts, where each part contributes to the whole's well-being.