The most accurate evaluation of the impact of feudalism after the fall of Western Rome from the provided options is:
Feudalism was an effective protective measure against Germanic tribes.
Feudalism emerged in response to the chaos and insecurity that followed the collapse of the Western Roman Empire, including threats from various groups, such as the Germanic tribes. The feudal system allowed for local lords to offer protection and service to vassals in exchange for loyalty and military service, which provided a measure of security in a fragmented and unstable political landscape.