Answer:
A. necessary parts of American life that are dying.
Step-by-step explanation:
The phrase "the withered leaves of industrial enterprise" implies that those things that are left dead and used due to industrial enterprise are like withered leaves. This refers to failed businesses. The phrase implies that failed business are important and necessary, just as leaves. But in the same way that withered leaves die and fall off when they no longer fulfill their job, failed businesses similarly die due to their lack of success in the entrepreneurial world.